Material for organic electroluminescence device and organic electroluminescence device utilizing the same

ABSTRACT

Provided is a material containing at least one phosphorescent metal complex, and a compound represented by the following formula (1): 
                         
wherein at least one of R 1  to R 3  is a 9-carbazolyl group which is optionally substituted or an azacarbazolyl group having 2 to 5 nitrogen atoms which is optionally substituted. The material for the organic electroluminescence device may be used as a host material or a hole transporting material. Also provided is an organic electroluminescence device which has an organic thin film layer that contains the material, and exhibits a high emitting efficiency, causes little pixel defects, is excellent in heat resistance, and has a long lifetime.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to Japanese patent applicationJP 2007-181142, filed on Jul. 10, 2007.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to materials for organicelectroluminescence devices and organic electroluminescence devicesusing the materials and, more particularly to materials for organicelectroluminescence devices which realize electroluminescence devicesexhibiting a high emitting efficiency, causing little pixel defects,exhibiting a high heat resistance and having a long lifetime.

2. Description of the Prior Art

An organic electroluminescence device (organic ELdevice) is aspontaneous emission device which utilizes the phenomenon offluorescence which occurs by the energy of recombination between holesinjected from an anode and electrons injected from a cathode byapplication of electric field. As the structure of organic EL devices, atwo-layered structure having a hole transporting (injecting) layer andan electron transporting/light emitting layer and a three-layeredstructure having a hole transporting (injecting) layer, a light emittinglayer and an electron transporting (injecting) layer are well known. Toincrease the efficiency of recombination of injected holes and electronsin laminated devices, the structure of the device and the process forforming the device have been studied.

It is recently proposed to use a light emitting layer of aphosphorescent material in addition to a light emitting layer of afluorescent material. A high efficiency of light emission is achieved byutilizing the excited singlet state and the excited triplet state of theorganic phosphorescent material in the light emitting layer. It isconsidered that the singlet exiton and the triplet exciton are formed ina proportion of 1:3 due to the difference in the spin multiplicity whenelectrons and holes are recombined in an organic EL device. Therefore,it is expected that an efficiency of light emission 3 to 4 times asgreat as that of a device utilizing only the fluorescent material can beachieved by utilizing a phosphorescent material.

To prevent the excited triplet state or the triplet exciton fromquenching, the organic EL devices described above are made into alaminate structure having an anode, a hole transporting layer, anorganic light emitting layer, an electron transporting layer (a holeblocking layer), an electron transporting layer and a cathode in thisorder, while using an organic light emitting layer made of a hostcompound and a phosphorescent compound (for example, Patent Documents1-6). In these Patent Documents, host materials having a dibenzofuranstructure or a dibenzothiophene structure are described. However, thereis nothing about their advantage in the device performance as comparedwith a host material having a carbazole structure.

Patent Documents 7 and 8 disclose compounds prepared by bonding acarbazole structure to dibenzo compounds. The proposed compounds areused in a host material for a blue phosphorescent device in examplesthereof. The compounds of the present invention are not taught and theeffect is uncertain.

Patent Documents 9, 10 and 11 disclose compounds prepared by bonding ananthracene structure to dibenzo compounds. However, the energy level ofthe excited triplet state of the proposed compounds is small because ofthe anthracene structure. Therefore, a blue phosphorescent material doesnot emit light even if any of the proposed compounds is used as a hostmaterial for the light emitting layer.

Patent Document 12 discloses dibenzofuran compounds essentially havingat least two polymerizable functional groups. If the host material of aphosphorescent device has in its molecule a polymerizable group such aspropenylene group, vinylene group and 4-propyl-2-pentenylene group whichis formed by introducing an unsaturated bond such as double bond andtriple bond, radicals are propagatedly generated in the device toadversely affect the emitting efficiency and lifetime.

-   [Patent Document 1] WO 05/101912-   [Patent Document 2] JP 5-109485A-   [Patent Document 3] JP 2004-002351A-   [Patent Document 4] WO 04/096945-   [Patent Document 5] JP 2002-308837A-   [Patent Document 6] WO 2005-113531-   [Patent Document 7] JP 2005-112765A-   [Patent Document 8] WO 2006-114966-   [Patent Document 9] JP 2005-314239A-   [Patent Document 10] JP 2007-77094A-   [Patent Document 11] JP 2007-63501A-   [Patent Document 12] JP 2007-110097A

SUMMARY OF THE INVENTION

The present invention has been made to overcome the above problems andhas an object of providing a material for organic EL devices whichrealizes an EL device exhibiting a high efficiency of light emission,causing little pixel defects, exhibiting a high heat resistance andhaving a long lifetime.

As a result of extensive research in view of achieving the above object,the inventors have found that a compound represented by the followingformula 1, which has a dibenzothiophene or dibenzofuran structure havingat its 2-position substituted with an aromatic hydrocarbon group,creates a excited triplet state having a sufficient energy level enoughto prevent the emitting efficiency of a blue phosphorescent complex frombeing reduced. It has been further found that the compound realizes ahighly efficient and highly heat-resistant organic EL device causinglittle pixel defects and having a long lifetime. The present inventionis based on these findings.

Thus, the preset invention provides a material for organicelectroluminescence devices for use in combination with at least onephosphorescent metal complex, which comprises a compound represented bythe following formula 1:

wherein R₁ to R₃ are each independently hydrogen atom, halogen atom,alkyl group having 1 to 40 carbon atoms which is optionally substituted,cycloalkyl group having 3 to 15 carbon atoms which is optionallysubstituted, heterocyclic group having 3 to 20 carbon atoms which isoptionally substituted, alkoxy group having 1 to 40 carbon atoms whichis optionally substituted, non-condensed aryl group having 6 to 40carbon atoms which is optionally substituted, condensed aryl grouphaving 10 to 18 carbon atoms which is optionally substituted, aryloxygroup having 6 to 20 carbon atoms which is optionally substituted,aralkyl group having 7 to 20 carbon atoms which is optionallysubstituted, arylamino group having 6 to 40 carbon atoms which isoptionally substituted, alkylamino group having 1 to 40 carbon atomswhich is optionally substituted, aralkylamino group having 7 to 60carbon atoms which is optionally substituted, arylcarbonyl group having7 to 40 carbon atoms which is optionally substituted, arylthio grouphaving 6 to 20 carbon atoms which is optionally substituted, alkylhalide group having 1 to 40 carbon atoms which is optionallysubstituted, or cyano group, with the proviso that at least one of R₁ toR₃ is 9-carbazolyl group which is optionally substituted orazacarbazolyl group having 2 to 5 nitrogen atoms which is optionallysubstituted;

R₆ and R₁₀ are each independently hydrogen atom or alkyl group having 1to 40 carbon atoms which is optionally substituted;

R₇ to R₉ are each independently hydrogen atom, halogen atom, alkyl grouphaving 1 to 40 carbon atoms which is optionally substituted, cycloalkylgroup having 3 to 15 carbon atoms which is optionally substituted,heterocyclic group having 3 to 20 carbon atoms which is optionallysubstituted, alkoxy group having 1 to 40 carbon atoms which isoptionally substituted, non-condensed aryl group having 6 to 40 carbonatoms which is optionally substituted, condensed aryl group having 10 to18 carbon atoms which is optionally substituted, aryloxy group having 6to 20 carbon atoms which is optionally substituted, aralkyl group having7 to 20 carbon atoms which is optionally substituted, arylamino grouphaving 6 to 40 carbon atoms which is optionally substituted, alkylaminogroup having 1 to 40 carbon atoms which is optionally substituted,aralkylamino group having 7 to 60 carbon atoms which is optionallysubstituted, arylcarbonyl group having 7 to 40 carbon atoms which isoptionally substituted, arylthio group having 6 to 20 carbon atoms whichis optionally substituted, alkyl halide group having 1 to 40 carbonatoms which is optionally substituted, or cyano group, with the provisothat when R₈ and R₉, or R₈ and R₇ are not bonded to each other therebydo not form a ring structure, at least one of R₇ to R₉ is 9-carbazolylgroup which is optionally substituted, azacarbazolyl group having 2 to 5nitrogen atoms which is optionally substituted, phenyl group which isoptionally substituted, dibenzofuranyl group which is optionallysubstituted, or dibenzothiophenyl group which is optionally substituted;

R₈ and R₉, or R₈ and R₇ are optionally bonded to each other to form aring structure which is optionally substituted, and R₇ or R₉ which doesnot form the ring structure is hydrogen atom, halogen atom, alkyl grouphaving 1 to 40 carbon atoms which is optionally substituted, cycloalkylgroup having 3 to 15 carbon atoms which is optionally substituted,heterocyclic group having 3 to 20 carbon atoms which is optionallysubstituted, alkoxy group having 1 to 40 carbon atoms which isoptionally substituted, non-condensed aryl group having 6 to 40 carbonatoms which is optionally substituted, condensed aryl group having 10 to18 carbon atoms which is optionally substituted, aryloxy group having 6to 20 carbon atoms which is optionally substituted, aralkyl group having7 to 20 carbon atoms which is optionally substituted, arylamino grouphaving 6 to 40 carbon atoms which is optionally substituted, alkylaminogroup having 1 to 40 carbon atoms which is optionally substituted,aralkylamino group having 7 to 60 carbon atoms which is optionallysubstituted, arylcarbonyl group having 7 to 40 carbon atoms which isoptionally substituted, arylthio group having 6 to 20 carbon atoms whichis optionally substituted, alkyl halide group having 1 to 40 carbonatoms which is optionally substituted, or cyano group, with the provisothat R₈ and R₉, or R₈ and R₇ together with a benzene ring to which R₇ toR₉ are bonded do not form carbazolyl group;

each of R₁ to R₃ and R₆ to R₁₀ does not have a polymerizable functionalgroup at its terminal end; and

X is sulfur atom or oxygen atom.

The present invention further provides an organic electroluminescencedevice which includes a cathode, an anode and an organic thin film layerhaving one or more layers, the organic thin film layer being interposedbetween the cathode and the anode and having a light emitting layercontaining a host material in combination with at least onephosphorescent metal complex, and at least one layer of the organic thinfilm layer containing the material for organic electroluminescencedevices mentioned above.

The organic EL device made using the material for organic EL devices ofthe present invention is free from pixel defects, highly efficient,highly heat resistant and durable for a long period of time.

DETAILED DESCRIPTION OF THE INVENTION

The material for organic EL devices of the invention is represented bythe following formula 1:

In the formula 1, R₁ to R₃ are each independently hydrogen atom, halogenatom, alkyl group having 1 to 40 carbon atoms which is optionallysubstituted, cycloalkyl group having 3 to 15 carbon atoms which isoptionally substituted, heterocyclic group having 3 to 20 carbon atomswhich is optionally substituted, alkoxy group having 1 to 40 carbonatoms which is optionally substituted, non-condensed aryl group having 6to 40 carbon atoms which is optionally substituted, condensed aryl grouphaving 10 to 18 carbon atoms which is optionally substituted, aryloxygroup having 6 to 20 carbon atoms which is optionally substituted,aralkyl group having 7 to 20 carbon atoms which is optionallysubstituted, arylamino group having 6 to 40 carbon atoms which isoptionally substituted, alkylamino group having 1 to 40 carbon atomswhich is optionally substituted, aralkylamino group having 7 to 60carbon atoms which is optionally substituted, arylcarbonyl group having7 to 40 carbon atoms which is optionally substituted, arylthio grouphaving 6 to 20 carbon atoms which is optionally substituted, alkylhalide group having 1 to 40 carbon atoms which is optionallysubstituted, or cyano group. At least one of R₁ to R₃ is 9-carbazolylgroup which is optionally substituted or azacarbazolyl group having 2 to5 nitrogen atoms which is optionally substituted. Examples of theazacarbazolyl groups (optional substituents are omitted for conciseness)are shown below, but not limited thereto.

R₆ and R₁₀ are each independently hydrogen atom or alkyl group having 1to 40 carbon atoms which is optionally substituted,

R₇ to R₉ are each independently hydrogen atom, halogen atom, alkyl grouphaving 1 to 40 carbon atoms which is optionally substituted, cycloalkylgroup having 3 to 15 carbon atoms which is optionally substituted,heterocyclic group having 3 to 20 carbon atoms which is optionallysubstituted, alkoxy group having 1 to 40 carbon atoms which isoptionally substituted, non-condensed aryl group having 6 to 40 carbonatoms which is optionally substituted, condensed aryl group having 10 to18 carbon atoms which is optionally substituted, aryloxy group having 6to 20 carbon atoms which is optionally substituted, aralkyl group having7 to 20 carbon atoms which is optionally substituted, arylamino grouphaving 6 to 40 carbon atoms which is optionally substituted, alkylaminogroup having 1 to 40 carbon atoms which is optionally substituted,aralkylamino group having 7 to 60 carbon atoms which is optionallysubstituted, arylcarbonyl group having 7 to 40 carbon atoms which isoptionally substituted, arylthio group having 6 to 20 carbon atoms whichis optionally substituted, alkyl halide group having 1 to 40 carbonatoms which is optionally substituted, or cyano group. When R₈ and R₉,or R₈ and R₇ are not bonded to each other thereby do not form a ringstructure, at least one of R₇ to R₉ is 9-carbazolyl group which isoptionally substituted, azacarbazolyl group having 2 to 5 nitrogen atomswhich is optionally substituted, phenyl group which is optionallysubstituted, dibenzofuranyl group which is optionally substituted, ordibenzothiophenyl group which is optionally substituted.

R₈ and R₉, or R₈ and R₇ are optionally bonded to each other to form aring structure which is optionally substituted. When forming the ringstructure, R₈ and R₉, or R₈ and R₇ together with the benzene ring towhich R₇ to R₈ are bonded preferably form, for example, the followingazacarbazole structure, dibenzofuran structure, dibenzothiophenestructure, or fluorene structure (substituents such as R₆ and optionalsubstituents are omitted for conciseness). However, R₈ and R₉, or R₈ andR₇ together with the benzene ring to which R₇ to R₉ are bonded do notform a carbazole structure.

When R₈ and R₉, or R₈ and R₇ are bonded to form the ring structure whichis optionally substituted, the remaining R₇ or R₉ which does not formthe ring structure is hydrogen atom, halogen atom, alkyl group having 1to 40 carbon atoms which is optionally substituted, cycloalkyl grouphaving 3 to 15 carbon atoms which is optionally substituted,heterocyclic group having 3 to 20 carbon atoms which is optionallysubstituted, alkoxy group having 1 to 40 carbon atoms which isoptionally substituted, non-condensed aryl group having 6 to 40 carbonatoms which is optionally substituted, condensed aryl group having 10 to18 carbon atoms which is optionally substituted, aryloxy group having 6to 20 carbon atoms which is optionally substituted, aralkyl group having7 to 20 carbon atoms which is optionally substituted, arylamino grouphaving 6 to 40 carbon atoms which is optionally substituted, alkylaminogroup having 1 to 40 carbon atoms which is optionally substituted,aralkylamino group having 7 to 60 carbon atoms which is optionallysubstituted, arylcarbonyl group having 7 to 40 carbon atoms which isoptionally substituted, arylthio group having 6 to 20 carbon atoms whichis optionally substituted, alkyl halide group having 1 to 40 carbonatoms which is optionally substituted, or cyano group.

Each of R₁ to R₃ and R₆ to R₁₀ (inclusive of substituent if substituted)does not have a polymerizable functional group, for example, vinylgroup, 1-methylvinyl group, 1-halovinyl group and 1-trihalomethylvinylgroup, at its terminal end.

The halogen atom includes, for example, fluorine, chlorine, bromine andiodine.

Examples of the alkyl group having 1 to 40 carbon atoms which isoptionally substituted include methyl group, ethyl group, propyl group,isopropyl group, n-butyl group, s-butyl group, isobutyl group, t-butylgroup, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group,n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group,n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecylgroup, n-heptadecyl group, n-octadecyl group, neopentyl group,1-methylpentyl group, 2-methylpentyl group, 1-pentylhexyl group,1-butylpentyl group, 1-heptyloctyl group, 3-methylpentyl group,hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group,2-hydroxyisobutyl group, 1,2-dihydroxyethyl group,1,3-dihydroxyisopropyl group, 2,3-dihydroxy-t-butyl group,1,2,3-trihydroxypropyl group, chloromethyl group, 1-chloroethyl group,2-chloroethyl group, 2-chloroisobutyl group, 1,2-dichloroethyl group,1,3-dichloroisopropyl group, 2,3-dichloro -t-butyl group,1,2,3-trichloropropyl group, bromomethyl group, 1-bromoethyl group,2-bromoethyl group, 2-bromoisobutyl group, 1,2-dibromoethyl group,1,3-dibromoisopropyl group, 2,3-dibromo-t-butyl group,1,2,3-tribromopropyl group, iodomethyl group, 1-iodoethyl group,2-iodoethyl group, 2-iodoisobutyl group, 1,2-diiodoethyl group,1,3-diiodoisopropyl group, 2,3-diiodo-t-butyl group, 1,2,3-triiodopropylgroup, aminomethyl group, 1-aminoethyl group, 2-aminoethyl group,2-aminoisobutyl group, 1,2-diaminoethyl group, 1,3-diaminoisopropylgroup, 2,3-diamino-t-butyl group, 1,2,3-triaminopropyl group,cyanomethyl group, 1-cyanoethyl group, 2-cyanoethyl group,2-cyanoisobutyl group, 1,2-dicyanoethyl group, 1,3-dicyanoisopropylgroup, 2,3-dicyano-t-butyl group, 1,2,3-tricyanopropyl group,nitromethyl group, 1-nitroethyl group, 2-nitroethyl group,1,2-dinitroethyl group, 2,3-dinitro-t-butyl group, and1,2,3-trinitropropyl group. Preferred are methyl group, ethyl group,propyl group, isopropyl group, n-butyl group, s-butyl group, isobutylgroup, t-butyl group, n-pentyl group, n-hexyl group, n-heptyl group,n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecylgroup, n-tridecyl group, n-tetradecyl group, n-pentadecyl group,n-hexadecyl group, n-heptadecyl group, n-octadecyl group, neopentylgroup, 1-methylpentyl group, 1-pentylhexyl group, 1-butylpentyl group,and 1-heptyloctyl group. The carbon number of the alkyl group (exclusiveof substituent) is preferably from 1 to 10.

Examples of the cycloalkyl group having 3 to 15 carbon atoms which isoptionally substituted include cyclopentyl group, cyclohexyl group,cyclooctyl group, and 3,3,5,5-tetramethylcyclohexyl group, withcyclohexyl group, cyclooctyl group and 3,5-tetramethylcyclohexyl groupbeing preferred. The carbon number of the cycloalkyl group (exclusive ofsubstituent) is preferably from 3 to 12.

Examples of the heterocyclic group having 3 to 20 carbon atoms which isoptionally substituted include 1-pyrrolyl group, 2-pyrrolyl group,3-pyrrolyl group, pyrazinyl group, 2-pyridinyl group, 1-imidazolylgroup, 2-imidazolyl group, 1-pyrazolyl group, 1-indolizinyl group,2-indolizinyl group, 3-indolizinyl group, 5-indolizinyl group,6-indolizinyl group, 7-indolizinyl group, 8-indolizinyl group,2-imidazopyridinyl group, 3-imidazopyridinyl group, 5-imidazopyridinylgroup, 6-imidazopyridinyl group, 7-imidazopyridinyl group,8-imidazopyridinyl group, 3-pyridinyl group, 4-pyridinyl group,1-indolyl group, 2-indolyl group, 3-indolyl group, 4-indolyl group,5-indolyl group, 6-indolyl group, 7-indolyl group, 1-isoindolyl group,2-isoindolyl group, 3-isoindolyl group, 4-isoindolyl group, 5-isoindolylgroup, 6-isoindolyl group, 7-isoindolyl group, 2-furyl group, 3-furylgroup, 2-benzofuranyl group, 3-benzofuranyl group, 4-benzofuranyl group,5-benzofuranyl group, 6-benzofuranyl group, 7-benzofuranyl group,1-isobenzofuranyl group, 3-isobenzofuranyl group, 4-isobenzofuranylgroup, 5-isobenzofuranyl group, 6-isobenzofuranyl group,7-isobenzofuranyl group, 2-quinolyl group, 3-quinolyl group, 4-quinolylgroup, 5-quinolyl group, 6-quinolyl group, 7-quinolyl group, 8-quinolylgroup, 1-isoquinolyl group, 3-isoquinolyl group, 4-isoquinolyl group,5-isoquinolyl group, 6-isoquinolyl group, 7-isoquinolyl group,8-isoquinolyl group, 2-quinoxalinyl group, 5-quinoxalinyl group,6-quinoxalinyl group, 1-carbazolyl group, 2-carbazolyl group,3-carbazolyl group, 4-carbazolyl group, 9-carbazolyl group,azacarbazole-1-yl group, azacarbazole-2-yl group, azacarbazole-3-ylgroup, azacarbazole-4-yl group, azacarbazole-5-yl group,azacarbazole-6-yl group, azacarbazole-7-yl group, azacarbazole -8-ylgroup, azacarbazole-9-yl group, 1-phenanthridinyl group,2-phenanthridinyl group, 3-phenanthridinyl group, 4-phenanthridinylgroup, 6-phenanthridinyl group, 7-phenanthridinyl group,8-phenanthridinyl group, 9-phenanthridinyl group, 10-phenanthridinylgroup, 1-acridinyl group, 2-acridinyl group, 3-acridinyl group,4-acridinyl group, 9-acridinyl group, 1,7-phenanthroline-2-yl group,1,7-phenanthroline-3-yl group, 1,7-phenanthroline-4-yl group,1,7-phenanthroline-5-yl group, 1,7-phenanthroline-6-yl group,1,7-phenanthroline-8-yl group, 1,7-phenanthroline-9-yl group,1,7-phenanthroline-10-yl group, 1,8-phenanthroline-2-yl group,1,8-phenanthroline-3-yl group, 1,8-phenanthroline-4-yl group,1,8-phenanthroline-5-yl group, 1,8-phenanthroline-6-yl group,1,8-phenanthroline-7-yl group, 1,8-phenanthroline-9-yl group,1,8-phenanthroline-10-yl group, 1,9-phenanthroline-2-yl group,1,9-phenanthroline-3-yl group, 1,9-phenanthroline-4-yl group,1,9-phenanthroline-5-yl group, 1,9-phenanthroline-6-yl group,1,9-phenanthroline-7-yl group, 1,9-phenanthroline-8-yl group,1,9-phenanthroline-10-yl group, 1,10-phenanthroline -2-yl group,1,10-phenanthroline-3-yl group, 1,10-phenanthroline-4-yl group,1,10-phenanthroline-5-yl group, 2,9-phenanthroline-1-yl group,2,9-phenanthroline-3-yl group, 2,9-phenanthroline-4-yl group,2,9-phenanthroline-5-yl group, 2,9-phenanthroline-6-yl group,2,9-phenanthroline-7-yl group, 2,9-phenanthroline-8-yl group,2,9-phenanthroline-10-yl group, 2,8-phenanthroline-1-yl group,2,8-phenanthroline-3-yl group, 2,8-phenanthroline-4-yl group,2,8-phenanthroline-5-yl group, 2,8-phenanthroline-6-yl group,2,8-phenanthroline-7-yl group, 2,8-phenanthroline-9-yl group,2,8-phenanthroline-10-yl group, 2,7-phenanthroline-1-yl group,2,7-phenanthroline-3-yl group, 2,7-phenanthroline-4-yl group,2,7-phenanthroline-5-yl group, 2,7-phenanthroline-6-yl group,2,7-phenanthroline-8-yl group, 2,7-phenanthroline-9-yl group,2,7-phenanthroline-10-yl group, 1-phenazinyl group, 2-phenazinyl group,1-phenothiazinyl group, 2-phenothiazinyl group, 3-phenothiazinyl group,4-phenothiazinyl group, 10-phenothiazinyl group, 1-phenoxazinyl group,2-phenoxazinyl group, 3-phenoxazinyl group, 4-phenoxazinyl group,10-phenoxazinyl group, 2-oxazolyl group, 4-oxazolyl group, 5-oxazolylgroup, 2-oxadiazolyl group, 5-oxadiazolyl group, 3-furazanyl group,2-thienyl group, 3-thienyl group, 2-methylpyrrole-1-yl group,2-methylpyrrole-3-yl group, 2-methylpyrrole-4-yl group,2-methylpyrrole-5-yl group, 3-methylpyrrole-1-yl group,3-methylpyrrole-2-yl group, 3-methylpyrrole-4-yl group,3-methylpyrrole-5-yl group, 2-t-butylpyrrole-4-yl group,3-(2-phenylpropyl)pyrrole-1-yl group, 2-methyl-1-indolyl group,4-methyl-1-indolyl group, 2-methyl-3-indolyl group, 4-methyl-3-indolylgroup, 2-t-butyl-1-indolyl group, 4-t-butyl-1-indolyl group,2-t-butyl-3-indolyl group, 4-t-butyl-3-indolyl group, 1-dibenzofuranylgroup, 2-dibenzofuranyl group, 3-dibenzofuranyl group, 4-dibenzofuranylgroup, 1-dibenzothiophenyl group, 2-dibenzothiophenyl group,3-dibenzothiophenyl group, 4-dibenzothiophenyl group, 1-silafluorenylgroup, 2-silafluorenyl group, 3-silafluorenyl group, 4-silafluorenylgroup, 1-germafluorenyl group, 2-germafluorenyl group, 3-germafluorenylgroup, and 4-germafluorenyl group.

Of the above, preferred are 2-pyridinyl group, 1-indolizinyl group,2-indolizinyl group, 3-indolizinyl group, 5-indolizinyl group,6-indolizinyl group, 7-indolizinyl group, 8-indolizinyl group,2-imidazopyridinyl group, 3-imidazopyridinyl group, 5-imidazopyridinylgroup, 6-imidazopyridinyl group, 7-imidazopyridinyl group,8-imidazopyridinyl group, 3-pyridinyl group, 4-pyridinyl group,1-indolyl group, 2-indolyl group, 3-indolyl group, 4-indolyl group,5-indolyl group, 6-indolyl group, 7-indolyl group, 1-isoindolyl group,2-isoindolyl group, 3-isoindolyl group, 4-isoindolyl group, 5-isoindolylgroup, 6-isoindolyl group, 7-isoindolyl group, 9-carbazolyl group,1-dibenzofuranyl group, 2-dibenzofuranyl group, 3-dibenzofuranyl group,4-dibenzofuranyl group, 1-dibenzothiophenyl group, 2-dibenzothiophenylgroup, 3-dibenzothiophenyl group, 4-dibenzothiophenyl group,1-silafluorenyl group, 2-silafluorenyl group, 3-silafluorenyl group,4-silafluorenyl group, 1-germafluorenyl group, 2-germafluorenyl group,3-germafluorenyl group, 4-germafluorenyl group, azacarbazole-1-yl group,azacarbazole-2-yl group, azacarbazole-3-yl group, azacarbazole-4-ylgroup, azacarbazole-5-yl group, azacarbazole-6-yl group,azacarbazole-7-yl group, azacarbazole-8-yl group, and azacarbazole-9-ylgroup. The carbon number of the heterocyclic group (exclusive ofsubstituent) is preferably from 3 to 14.

The alkoxy group having 1 to 40 carbon atoms which is optionallysubstituted is represented by —OY wherein Y and its preferred examplesare the same as the alkyl groups mentioned above.

Examples of the non-condensed aryl group having 6 to 40 carbon atomswhich is optionally substituted include phenyl group, 2-biphenylylgroup, 3-biphenylyl group, 4-biphenylyl group, p-terphenyl-4-yl group,p-terphenyl-3-yl group, p-terphenyl-2-yl group, m-terphenyl-4-yl group,m-terphenyl-3-yl group, m-terphenyl-2-yl group, o-tolyl group, m-tolylgroup, p-tolyl group, p-t-butylphenyl group, p-(2-phenylpropyl)phenylgroup, 4′-methylbiphenylyl group, 4″-t-butyl-p-terphenyl-4-yl group,o-cumenyl group, m-cumenyl group, p-cumenyl group, 2,3-xylyl group,3,4-xylyl group, 2,5-xylyl group, mesityl group, and m-quaterphenylgroup, with phenyl group, 2-biphenylyl group, 3-biphenylyl group,4-biphenylyl group, m-terphenyl-4-yl group, m-terphenyl-3-yl group,m-terphenyl-2-yl group, p-tolyl group, 3,4-xylyl group, andm-quaterphenyl-2-yl group being preferred. The carbon number of thenon-condensed aryl group (exclusive of substituent) is preferably from 6to 24.

Examples of the condensed aryl group having 10 to 18 carbon atoms whichis optionally substituted include 1-naphthyl group, 2-naphthyl group,1-phenanthrenyl group, 2-phenanthrenyl group, 3-phenanthrenyl group,4-phenanthrenyl group, 9-phenanthrenyl group, 1-triphenylenyl group,2-triphenylenyl group, 3-triphenylenyl group, 4-triphenylenyl group,1-chrysenyl group, 2-chrysenyl group, 3-chrysenyl group, 4-chrysenylgroup, 5-chrysenyl group, and 6-chrysenyl group.

The aryloxy group having 6 to 20 carbon atoms which is optionallysubstituted is represented by —OAr wherein Ar and its preferred examplesare the same as the non-condensed aryl groups mentioned above.

Examples of the aralkyl group having 7 to 20 carbon atoms which isoptionally substituted include benzyl group, 1-phenylethyl group,2-phenylethyl group, 1-phenylisopropyl group, 2-phenylisopropyl group,phenyl-t-butyl group, α-naphthylmethyl group, 1-α-naphthylethyl group,2-α-naphthylethyl group, 1-α-naphthylisopropyl group,2-α-naphthylisopropyl group, β-naphthylmethyl group, 1-β-naphthylethylgroup, 2-β-naphthylethyl group, 1-β-naphthylisopropyl group,2-β-naphthylisopropyl group, 1-pyrrolylmethyl group, 2-(1-pyrrolyl)ethylgroup, p-methylbenzyl group, m-methylbenzyl group, o-methylbenzyl group,p-chlorobenzyl group, m-chlorobenzyl group, o-chlorobenzyl group,p-bromobenzyl group, m-bromobenzyl group, o-bromobenzyl group,p-iodobenzyl group, m-iodobenzyl group, o-iodobenzyl group,p-hydroxybenzyl group, m-hydroxybenzyl group, o-hydroxybenzyl group,p-aminobenzyl group, m-aminobenzyl group, o-aminobenzyl group,p-nitrobenzyl group, m-nitrobenzyl group, o-nitrobenzyl group,p-cyanobenzyl group, m-cyanobenzyl group, o-cyanobenzyl group,1-hydroxy-2-phenylisopropyl group, and 1-chloro-2-phenylisopropyl group,with benzyl group, p-cyanobenzyl group, m-cyanobenzyl group,o-cyanobenzyl group, 1-phenylethyl group, 2-phenylethyl group,1-phenylisopropyl group, and 2-phenylisopropyl group being preferred.The alkyl moiety of the aralkyl group has preferably from 1 to 8 carbonatoms, and the aryl moiety (inclusive of heteroaryl) has preferably from6 to 18 carbon atoms.

Each of the arylamino group having 6 to 40 carbon atoms which isoptionally substituted, the alkylamino group having 1 to 40 carbon atomswhich is optionally substituted and the aralkylamino group having 7 to60 carbon atoms which is optionally substituted is represented by—NQ₁Q₂, wherein Q₁ and Q₂ are each independently selected from the alkylgroups, aryl groups and aralkyl groups described above. Similarly,preferred examples of Q₁ and Q₂ are the same as those described above.

The arylcarbonyl group having 7 to 40 carbon atoms which is optionallysubstituted is represented by —COAr₂, wherein Ar₂ and its preferredexamples are the same as the aryl groups mentioned above.

The arylthio group having 6 to 20 carbon atoms which is optionallysubstituted is a group derived from the aryloxy group —OAr bysubstituting sulfur atom for the oxygen atom. Preferred arylthio groupsare derived from the preferred aryloxy groups in the same manner.

The alkyl halide group having 1 to 40 carbon atoms which is optionallysubstituted is, for example, derived from the alkyl group mentionedabove by substituting halogen atom for at least one hydrogen atom.Preferred alkyl halide groups are derived from the preferred alkylgroups in the same manner.

The compound of the formula 1 is preferably represented by any of thefollowing formulae 2 to 5:

In the formulae 2 to 5, R₁ to R₃, R₆ to R₁₀ and X are the same asdefined above. The definitions of R₁₈ to R₂₉ are the same as thedefinition of R₁ to R₃ except for the proviso.

Examples of the substituent groups in the definitions of R₁ to R₃, R₆ toR₁₀ and R₁₈ to R₂₉ in the formulae 1 to 5 include alkyl group having 1to 8 carbon atoms (methyl group, ethyl group, propyl group, isopropylgroup, n-butyl group, s-butyl group, isobutyl group, t-butyl group,n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group);hydroxyalkyl group having 1 to 5 carbon atoms (hydroxymethyl group,1-hydroxyethyl group, 2-hydroxyethyl group, 2-hydroxyisobutyl group,1,2-dihydroxyethyl group, 1,3-dihydroxyisopropyl group,2,3-dihydroxy-t-butyl group, 1,2,3-trihydroxypropyl group); haloalkylgroup having 1 to 4 carbon atoms (chloromethyl group, 1-chloroethylgroup, 2-chloroethyl group, 2-chloroisobutyl group, 1,2-dichloroethylgroup, 1,3-dichloroisopropyl group, 2,3-dichloro-t-butyl group,1,2,3-trichloropropyl group, bromomethyl group, 1-bromoethyl group,2-bromoethyl group, 2-bromoisobutyl group, 1,2-dibromoethyl group,1,3-dibromoisopropyl group, 2,3-dibromo-t-butyl group,1,2,3-tribromopropyl group, iodomethyl group, 1-iodoethyl group,2-iodoethyl group, 2-iodoisobutyl group, 1,2-diiodoethyl group,1,3-diiodoisopropyl group, 2,3-diiodo-t-butyl group, 1,2,3-triiodopropylgroup); aminoalkyl group having 1 to 4 carbon atoms (aminomethyl group,1-aminoethyl group, 2-aminoethyl group, 2-aminoisobutyl group,1,2-diaminoethyl group, 1,3-diaminoisopropyl group, 2,3-diamino-t-butylgroup, 1,2,3-triaminopropyl group); cyanoalkyl group having 1 to 4carbon atoms (cyanomethyl group, 1-cyanoethyl group, 2-cyanoethyl group,2-cyanoisobutyl group, 1,2-dicyanoethyl group, 1,3-dicyanoisopropylgroup, 2,3-dicyano-t-butyl group, 1,2,3-tricyanopropyl group);nitroalkyl group having 1 to 5 carbon atoms (nitromethyl group,1-nitroethyl group, 2-nitroethyl group, 2-nitroisobutyl group,1,2-dinitroethyl group, 1,3-dinitroisopropyl group, 2,3-dinitro-t-butylgroup, 1,2,3-trinitropropyl group); (alkyl)cycloalkyl group having 3 to10 carbon atoms (cyclopropyl group, cyclobutyl group, cyclopentyl group,cyclohexyl group, 4-methylcyclohexyl group, 1-adamantyl group,2-adamantyl group, 1-norbornyl group, 2-norbornyl group); having 1 to 60carbon atoms alkoxy group(ethoxy group, methoxy group, isopropoxy group,n-propoxy group, s-butoxy group, t-butoxy group, pentoxy group, hexyloxygroup); cycloalkoxy group having 3 to 6 carbon atoms (cyclopentoxygroup, cyclohexyloxy group); aryl group having 5 to 40 ring atoms; aminogroup substituted with aryl group having 5 to 40 ring atoms; ester grouphaving aryl group with 5 to 40 ring atoms; ester group having alkylgroup with 1 to 60 carbon atoms; cyano group; nitro group; halogen atom;hydroxyl group; amino group; substituted or non-substituted carbazolylgroup (1-carbazolyl group, 2-carbazolyl group, 3-carbazolyl group,4-carbazolyl group, 9-carbazolyl group); substituted or non-substituteddibenzofuranyl group (1-dibenzofuranyl group, 2-dibenzofuranyl group,3-dibenzofuranyl group, 4-dibenzofuranyl group); and substituted or nonsubstituted dibenzothiophenyl group (1-dibenzothiophenyl group,2-dibenzothiophenyl group, 3-dibenzothiophenyl group,4-dibenzothiophenyl group). The substituent groups for carbazolyl group,dibenzofuranyl group, and dibenzothiophenyl group are selected from thegroups recited above.

At least one of R₇, R₈ and R₂₀ to R₂₄ of the formula 2; at least one ofR₇, R₉ and R₂₀ to R₂₄ of the formula 3; at least one of R₇ and R₂₁ toR₂₃ of the formula 4; and at least one of R₇, R₈, R₂₀ and R₂₂ to R₂₉ ofthe formula 5 are preferably selected from substituted ornon-substituted 9-carbazolyl group, substituted or non-substituteddibenzofuranyl group, substituted or non-substituted azacarbazolyl grouphaving 2 to 5 nitrogen atoms and substituted or non-substituteddibenzothiophenyl group.

The compound represented by any of the formulae 1 to 5 has a tripletenergy gap of 2.3 to 3.2 eV. Examples of the compounds of the presentinvention are shown below, although not limited thereto.

The compounds of the formula 1 may be easily synthesized bySuzuki-Miyaura reaction between an organic boronic acid and an arylhalide according to the following reaction scheme.

The material for organic EL devices of the present invention arepreferably used as a host material for the light emitting layer and ahole transporting material.

The organic EL devices of the present invention will be described below.The organic EL devices have an organic thin film having one or morelayers between the cathode and the anode. At least one of the layers ofthe organic thin film is a light emitting layer which comprises a hostmaterial for use in combination with at least one phosphorescent metalcomplex. At least one layer of the organic thin film contains thematerial for organic EL devices of the present invention.

The multi-layered organic EL devices have a multi-layered laminatestructure such as anode/hole transporting layer (hole injectinglayer)/light emitting layer/cathode, anode/light emitting layer/electrontransporting layer (electron injecting layer)/cathode, anode/holetransporting layer (hole injecting layer)/light emitting layer/electrontransporting layer (electron injecting layer)/cathode, and anode/holetransporting layer (hole injecting layer)/light emitting layer/holebarrier layer/electron transporting layer (electron injectinglayer)/cathode.

The light emitting layer of the organic EL devices preferably containsthe material for organic EL devices as the host material. Further, thelight emitting layer comprises a host material, preferably the materialfor organic EL devices, and a phosphorescent material. Preferredexamples of the phosphorescent material are compounds containing iridium(Ir), osmium (Os) or platinum (Pt) because of their high quantum yieldof phosphorescence and their capability of enhancing the externalquantum efficiency of light emitting devices, with metal complexes suchas iridium complexes, osmium complexes and platinum complexes being morepreferred, iridium complexes and platinum complexes being still morepreferred, and ortho-metallated iridium complexes being most preferred.Preferred examples of the ortho-metallated iridium complexes are shownbelow.

In another preferred embodiment of the organic EL devices, the lightemitting layer contains the host material and a phosphorescent material,for example, a blue-light emitting metal complex having a maximumemitting wavelength of 500 nm or less. Examples of the blue-lightemitting metal complex include K-1, K-2, K-3, K-10, K-11, K-12, K-15,K-16, K-17, K-20, and K-21 described above.

Still another preferred organic EL device includes a hole transportinglayer (hole injecting layer) which contains the material for organic ELdevices of the invention.

In the organic EL devices of the invention, a reducing dopant ispreferably added to the interfacial region between the cathode and theorganic thin film layer. Examples of the reducing dopant include atleast one compound selected from alkali metals, alkali metal complexes,alkali metal compounds, alkaline earth metals, alkaline earth metalcomplexes, alkaline earth metal compounds, rare earth metals, rare earthmetal complexes, and rare earth metal compounds.

Examples of the alkali metals include Na (work function: 2.36 eV), K(work function: 2.28 eV), Rb (work function: 2.16 eV), and Cs (workfunction: 1.95 eV), with those having a work function of 2.9 eV or lessbeing particularly preferred. Preferred is K, Rb or Cs, more preferredis Rb or Cs, and most preferred is Cs.

Examples of the alkaline earth metals include Ca (work function: 2.9eV), Sr (work function: 2.0 to 2.5 eV), and Ba (work function: 2.52 eV),with those having a work function of 2.9 eV or less being particularlypreferred.

Examples of the rare earth metals include Sc, Y, Ce, Tb and Yb, withthose having a work function of 2.9 eV or less being particularlypreferred.

Particularly, the preferred metals mentioned above having a highreducing ability. Therefore, a relatively small amount of additionthereof to the electron injecting zone improves the luminance ofemission and prolongs the lifetime.

Examples of the alkali metal compounds include alkali oxides such asLi₂O, Cs₂O and K₂O and alkali halides such as LiF, NaF, CsF and KF, withLiF, Li₂O and NaF being preferred.

Examples of the alkaline earth metal compounds include BaO, SrO, CaO andmixtures thereof such as Ba_(x)Sr_(1-x)O (0<x<1) and Ba_(x)Ca_(1-x)O(0<x<1), with BaO, SrO and CaO being preferred.

Examples of the rare earth metal compounds include YbF₃, ScF₃, ScO₃,Y₂O₃, Ce₂O₃, GdF₃ and TbF₃, with YbF₃, ScF₃, and TbF₃ being preferred.

The alkali metal complexes, alkaline earth metal complexes and rareearth metal complexes are not particularly limited as long as containingat lease one metal ions selected from alkali metal ions, alkaline earthmetal ions and rare earth metal ions. Examples of the lingand preferablyinclude, but not limited to, quinolinol, benzoquinolinol, acridinol,phenanthridinol, hydroxyphenyloxazole, hydroxyphenylthiazole,hydroxydiaryloxadiazole, hydroxydiarylthiadiazole,hydroxyphenylpyridine, hydroxyphenylbenzimidazole, hydroxybenzotriazole,hydroxyfulborane, bipyridine, phenanthroline, phthalocyanine, porphyrin,cyclopentadiene, β-diketones, azomethines, and derivatives thereof.

The reducing dopant is added to the interfacial region preferably in theform of layers or islands by a resistance-heating vapor deposition inwhich the reducing dopant is vapor-deposited while vapor-depositing anorganic material (a light emitting material or an electron injectingmaterial for forming the interfacial region) at the same time, therebydispersing the reducing dopant in the organic material. The dispersionconcentration is 100:1 to 1:100, preferably 5:1 to 1:5 when expressed bya molar ratio of the the organic material to the reducing dopant.

When adding the reducing dopant in the form of layer, the reducingdopant is solely vapor-deposited by the resistance-heating vapordeposition into a layer preferably having a thickness of 0.1 to 15 nmafter forming an interfacial organic layer from a light emittingmaterial or an electron injecting material.

When adding the reducing dopant in the form of islands, the reducingdopant is solely vapor-deposited by the resistance-heating vapordeposition into a form of islands preferably having a thickness of 0.05to 1 nm after forming an interfacial organic layer from a light emittingmaterial or an electron injecting material.

The molar ratio of the main components of the organic EL devices of theinvention (light emitting material and electron injecting material) andthe reducing dopant is preferably 5:1 to 1:5 and more preferably 2:1 to1:2.

In still another preferred embodiment of the invention, the organic ELdevice has an electron injecting layer between the light emitting layerand the cathode, and the electron injecting layer mainly comprises anitrogen-containing cyclic derivative which is different from theorganic EL material of the present invention. The electron transportingmaterial for the electron injecting layer is preferably an aromaticheterocyclic compound having one or more heteroatoms in its molecule,particularly an aromatic nitrogen-containing cyclic compound.

For example, the aromatic nitrogen-containing cyclic compound ispreferably a nitrogen-containing, cyclic metal chelate complexrepresented by the following formula A:

In the formula A, R² to R⁷ are each independently hydrogen atom, halogenatom, oxy group, or amino group or hydrocarbon group having 1 to 40carbon atoms, each being optionally substituted.

Examples of the halogen atom are the same as mentioned above. Examplesof the amino group which is optionally substituted include the samegroups which are recited as the alkylamino group, arylamino group, andaralkylamino group mentioned above.

Example of the hydrocarbon group having 1 to 40 carbon atoms includealkyl group, alkenyl group, cycloalkyl group, alkoxy group, aryl group,heterocyclic group, aralkyl group, aryloxy group, and alkoxycarbonylgroup, each being optionally substituted. Examples of the alkyl group,alkenyl group, cycloalkyl group, alkoxy group, aryl group, heterocyclicgroup, aralkyl group, and aryloxy group are the same as those mentionedabove. The alkoxycarbonyl group is represented by —COOY′ wherein Y′ isthe same alkyl group as mentioned above.

M in the formula A is aluminum (Al), gallium (Ga) or indium (In), withIn being preferred.

L in the formula A is a group represented by the following formula A′ orA″:

wherein R⁸ to R¹² are each independently hydrogen atom or hydrocarbongroup having 1 to 40 carbon atoms which is optionally substituted, thegroups adjacent to each other optionally forming a ring structure. R¹³to R²⁷ are each independently hydrogen atom or hydrocarbon group having1 to 40 carbon atoms which is optionally substituted, the groupsadjacent to each other optionally forming a ring structure.

Examples of the hydrocarbon group having 1 to 40 carbon atoms of theformulae A′ and A″ are the same groups as those recited for R² to R⁷.Examples of the bivalent group which is formed by the adjacent groups ofR⁸ to R¹² or R¹³ to R²⁷ for forming a ring structure includetetramethyle group, pentamethyle group, hexamethyle group,diphenylmethane-2,2′-diyl group, diphenylethane-3,3′-diyl group, anddiphenylpropane-4,4′-diyl group.

Specific examples of the nitrogen-containing, cyclic metal chelatecomplex are shown below, although not limited thereto.

Another preferred example of the aromatic, nitrogen-containing cycliccompound includes a nitrogen-containing, five-membered cyclic compound.The nitrogen-containing, five-membered ring may include imidazole ring,triazole ring, tetrazole ring, oxadiazole ring, thiadiazole ring,oxatriazole ring, and thiatriazole ring. The nitrogen-containing,five-membered cyclic compound has a skeletal structure such asbenzimidazole ring, benzotriazole ring, pyridinoimidazole ring,pyrimidinoimidazole ring, and pyridazinoimidazole ring, and ispreferably represented by the following formula B:

In the formula B, L^(B) is a mono- to tetravalent bonding group such ascarbon atom, silicon atom, nitrogen atom, boron atom, oxygen atom,sulfur atom, metal (barium, beryllium, etc.), aromatic hydrocarbon ring,and heteroaromatic ring, with carbon atom, nitrogen atom, silicon atom,boron atom, oxygen atom, sulfur atom, aryl group and heteroaromaticgroup being preferred, and carbon atom, silicon atom, aryl group andheteroaromatic group being more preferred.

The aryl group or heteroaromatic group for L^(B) may be substituted. Thesubstituent group is preferably alkyl group, alkenyl group,alkynylgroup, aryl group, amino group, alkoxy group, aryloxy group, acylgroup, alkoxycarbonyl group, aryloxycarbonyl group, acyloxy group,acylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group,sulfonylamino group, sulfamoyl group, carbamoyl group, alkylthio group,arylthio group, sulfonyl group, halogen atom, cyano group, orheteroaromatic group; more preferably alkyl group, aryl group, alkoxygroup, aryloxy group, halogen atom, cyano group, or heteroaromaticgroup; still more preferably alkyl group, aryl group, alkoxy group,aryloxy group, or heteroaromatic group; and particularly preferablyalkyl group, aryl group, alkoxy group, or heteroaromatic group.

Preferred examples of L^(B) are shown below.

X^(B2) in the formula B is —O—, —S— or ═N—R^(B2), preferably —O— or═N—R^(B2), and more preferably ═N—R^(B2). R^(B2) is hydrogen atom,aliphatic hydrocarbon group, aryl group or heterocyclic group.

The aliphatic hydrocarbon group for R^(B2) may be linear, branched orcyclic and includes alkyl groups having preferably 1 to 20 carbon atoms,more preferably 1 to 12 carbon atoms and particularly preferably 1 to 8carbon atoms such as methyl, ethyl, isopropyl, t-butyl, n-octyl,n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, and cyclohexyl; alkenylgroups having preferably 2 to 20 carbon atoms, more preferably 2 to 12carbon atoms and particularly preferably 2 to 8 carbon atoms such asvinyl, allyl, 2-butenyl, and 3-pentenyl; and alkynyl groups havingpreferably 2 to 20 carbon atoms, more preferably 2 to 12 carbon atomsand particularly preferably 2 to 8 carbon atoms such as propargyl and3-pentynyl, with alkyl groups being preferred.

The aryl group for R^(B2) is a non-condensed or condensed aryl group andhas preferably 6 to 30 carbon atoms, more preferably 6 to 20 carbonatoms and still more preferably 6 to 12 carbon atoms. Examples thereofinclude phenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl,2-methoxyphenyl, 3-trifluoromethylphenyl, pentafluorophenyl, 1-naphthyl,and 2-naphthyl.

The heterocyclic group for R^(B2) is a non-condensed or condensedheterocyclic group, preferably a heteroaromatic group having at leastone atom selected from nitrogen atom, oxygen atom, sulfur atom andselenium atom, and has preferably 1 to 20 carbon atoms, more preferably1 to 12 carbon atoms and still more preferably 2 to 10 carbon atoms.Examples of the basic structure of the heterocyclic group includepyrrolidine, piperidine, piperazine, morpholine, thiophene, selenophene,furan, pyrrole, imidazole, pyrazole, pyridine, pyrazine, pyridazine,pyrimidine, triazole, triazine, indole, indazole, purine, thiazoline,thiazole, thiadiazole, oxazoline, oxazole, oxadiazole, quinoline,isoquinoline, phthalazine, naphthyridine, quinoxaline, quinazoline,cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole,benzimidazole, benzoxazole, benzothiazole, benzotriazole,tetraazaindene, carbazole, and azepine, with furan, thiophene, pyridine,pyrazine, pyrimidine, pyridazine, triazine, quinoline, phthalazine,naphthyridine, quinoxaline, and quinazoline being preferred, furan,thiophene, pyridine, and quinoline being more preferred, and quinolinebeing still more preferred.

The aliphatic hydrocarbon group, aryl group and heterocyclic group forR^(B2) may be substituted. The substituent groups and preferredsubstituent groups are the same as the substituent groups for L^(B)mentioned above.

R^(B2) is preferably aliphatic hydrocarbon group, aryl group orheterocyclic group, more preferably aliphatic hydrocarbon group or arylgroup (having preferably 6 to 30 carbon atoms, more preferably 6 to 20carbon atoms, and still more preferably 6 to 12 carbon atoms), and stillmore preferably aliphatic hydrocarbon group (having preferably 1 to 20carbon atoms, more preferably 1 to 12 carbon atoms, and still morepreferably 2 to 10 carbon atoms).

Z^(B2) is a group of atoms to form an aromatic ring. The aromatic ringformed by Z^(B2) is either of an aromatic hydrocarbon ring or aheteroaromatic ring. Examples there of include benzene ring, pyridinering, pyrazine ring, pyrimidine ring, pyridazine ring, triazine ring,pyrrole ring, furan ring, thiophene ring, selenophene ring, tellurophenering, imidazole ring, thiazole ring, selenazole ring, tellurazole ring,thiadiazole ring, oxadiazole ring, and pyrazole ring, with benzene ring,pyridine ring, pyrazine ring, pyrimidine ring, and pyridazine ring beingpreferred, benzene ring, pyridine ring, and pyrazine ring being morepreferred, benzene ring and pyridine ring being still more preferred,and pyridine ring being particularly preferred.

The aromatic ring formed by Z^(B2) may be fused with another ring toform a condensed ring and may be substituted. Examples of thesubstituent group are the same as the substituent groups for L^(B) andpreferably alkyl group, alkenyl group, alkynylgroup, aryl group, aminogroup, alkoxy group, aryloxy group, acyl group, alkoxycarbonyl group,aryloxycarbonyl group, acyloxy group, acylamino group,alkoxycarbonylamino group, aryloxycarbonylamino group, sulfonylaminogroup, sulfamoyl group, carbamoyl group, alkylthio group, arylthiogroup, sulfonyl group, halogen atom, cyano group, and heterocyclicgroup; more preferably alkyl group, aryl group, alkoxy group, aryloxygroup, halogen atom, cyano group, and heterocyclic group; still morepreferably alkyl group, aryl group, alkoxy group, aryloxy group, andheteroaromatic group; and particularly preferably alkyl group, arylgroup, alkoxy group, and heteroaromatic group.

n^(B2) is an integer of 1 to 6, preferably an integer of 1 to 4, andstill more preferably 2 or 3.

The nitrogen-containing five-membered cyclic compound of the formula Bis preferably represented by the following formula B′:

In the formula B′, R^(B71), R^(B72), R^(B73) and their preferredexamples are each independently the same as defined in R^(B2) of theformula B.

Z^(B71), Z^(B72), Z^(B73) and their preferred examples are eachindependently the same as defined in Z^(B2) of the formula B.

L^(B71), L^(B72) and L^(B73) are each independently single bond orbivalent group as defined in L^(B) of the formula B, preferably singlebond, bivalent aromatic hydrocarbon group, bivalent heteroaromatic groupor bivalent bonding group composed of a combination thereof, with singlebond being preferred. L^(B71), L^(B72) and L^(B73) may be substituted.The substituent groups and preferred substituent groups are the same asthe substituent groups for L^(B) of the formula B.

Y is nitrogen atom, 1,3,5-benzenetriyl group or 2,4,6-triazinetriylgroup. The 1,3,5-benzenetriyl group may be substituted at2,4,6-position, for example, by alkyl group, aromatic hydrocarbon groupor halogen atom.

Specific examples of the nitrogen-containing five-membered cycliccompound of the formula B or B′ are shown below, although not limitedthereto.

In addition to the aromatic, nitrogen-containing cyclic compoundmentioned above, the compounds for forming the electron injecting layerand electron transporting layer may further include anelectron-deficient, nitrogen-containing cyclic compound which has astructure combining an electron-deficient, nitrogen-containing 5- or6-membered cyclic skeleton with a substituted or non-substituted indoleskeleton, substituted or non-substituted carbazole skeleton, orsubstituted or non-substituted azacarbazole skeleton. Preferredelectron-deficient, nitrogen-containing 5 or 6-membered cyclic skeletonincludes each skeleton of pyridine, pyrimidine, pyrazine, triazine,triazole, oxadiazole, pyrazole, imidazole, quinoxaline, pyrrole, and acondensed skeleton thereof such as benzimidazole and imidazopyridine.The combination between the pyridine, pyrimidine, pyrazine or triazineskeleton with the carbazole, indole, azacarbazole or quinoxalineskeleton is preferred. Each skeleton may be either substituted or notsubstituted.

Examples of the electron-deficient, nitrogen-containing cyclic compoundare shown below.

The electron injecting layer and electron transporting layer may be asingle-layered structure or multi-layered structure of layers having thesame composition or different compositions, each layer being made of oneor more kinds of the materials mentioned above, preferably a compoundhaving a nitrogen-containing heterocyclic group with a low π-electrondensity.

In addition to the nitrogen-containing cyclic compound and theelectron-deficient, nitrogen-containing cyclic compound, the electroninjecting layer is preferably incorporated with an inorganic compoundsuch as insulating material and semiconductor. The insulating materialor semiconductor incorporated into the electron injecting layereffectively prevents the leak of electric current to enhance theelectron injecting properties.

The insulating material is preferably at least one metal compoundselected from the group consisting of alkali metal chalcogenides,alkaline earth metal chalcogenides, alkali metal halides and alkalineearth metal halides. The metal compound incorporated into the electroninjecting layer further enhances the electron injecting properties.Preferred examples of the alkali metal chalcogenides include Li₂O, K₂O,Na₂S, Na₂Se and Na₂O, and preferred examples of the alkaline earth metalchalcogenides include CaO, BaO, SrO, BeO, BaS and CaSe. Preferredexamples of the alkali metal halides include LiF, NaF, KF, LiCl, KCl andNaCl. Examples of the alkaline earth metal halides include fluoridessuch as CaF₂, BaF₂, SrF₂, MgF₂ and BeF₂ and halides other thanfluorides.

Examples of the semiconductor may include oxide, nitride or oxynitrideeach containing at least one element selected from the group consistingof Ba, Ca, Sr, Yb, Al, Ga, In, Li, Na, Cd, Mg, Si, Ta, Sb and Zn. Thesemiconductor may be used singly or in combination of two or more. Theinorganic compound included in the electron injecting layer preferablyforms a microcrystalline or amorphous insulating thin film. When theelectron injecting layer is formed from such an insulating thin film,the thin film is made more uniform to decrease the pixel defects such asdark spots. Examples of such inorganic compound include alkali metalchalcogenides, alkaline earth metal chalcogenides, alkali metalhalidesand alkaline earth metalhalide, each being described above.

The electron injecting layer may be included with the reducing dopantdescribed above.

Since the anode of the organic EL devices has a function of injectingholes into the hole transporting layer or light emitting layer, theanode preferably has a work function of 4.5 eV or more. Examples of thematerial for the anode include indium tin oxide (ITO), tin oxide (NESA),gold, silver, platinum and copper. Since the cathode has a function ofinjecting electrons into the electron injecting layer or light emittinglayer, the material for the cathode preferably has a small workfunction. Examples of the material for the cathode include, but notlimited to, indium, aluminum, magnesium, magnesium-indium alloy,magnesium-aluminum alloy, aluminum-lithium alloy,aluminum-scandium-lithium alloy, and magnesium-silver alloy.

The method of forming each layer of the organic EL devices is notcritical, and a known method such as a vacuum vapor deposition methodand a spin coating method may be employed. The organic thin film layercontaining the material for organic EL devices of the invention can beformed by a known method such as a vacuum vapor deposition method,molecular beam epitaxy method (MBE method) and a solution coatingmethod, for example, a dipping method, spin coating method, a castingmethod, a bar coating method and a roll coating method.

The thickness of each organic layer of the organic EL devices is notparticularly limited. Generally, an excessively thin layer likely causesdefects such as pin holes, and an excessively thick layer requires ahigh applied voltage to decrease the efficiency. The thickness ispreferably from several nanometers to 1 μm.

The hole injecting/transporting layer is formed from an aromatic aminecompound, preferably the aromatic amine derivative represented by thefollowing formula I:

In the formula I, Ar¹ to Ar⁴ are each independently aryl group(inclusive of heteroaryl group) having 5 to 50 ring atoms.

Examples of the aryl group having 5 to 50 ring atoms include phenylgroup, 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthrylgroup, 9-anthryl group, 1-phenanthryl group, 2-phenanthryl group,3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group,1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group,1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group, 2-biphenylyl group,3-biphenylyl group, 4-biphenylyl group, p-terphenyl-4-yl group,p-terphenyl-3-yl group, p-terphenyl-2-yl group, m-terphenyl-4-yl group,m-terphenyl-3-yl group, m-terphenyl-2-yl group, o-tolyl group, m-tolylgroup, p-tolyl group, p-t-butylphenyl group, p-(2-phenylpropyl)phenylgroup, 3-methyl-2-naphthyl group, 4-methyl-1-naphthyl group,4-methyl-1-anthryl group, 4′-methylbiphenylyl group,4″-t-butyl-p-terphenyl-4-yl group, fluoranthenyl group, fluorenyl group,1-pyrrolyl group, 2-pyrrolyl group, 3-pyrrolyl group, pyrazinyl group,2-pyridinyl group, 3-pyridinyl group, 4-pyridinyl group, 1-indolylgroup, 2-indolyl group, 3-indolyl group, 4-indolyl group, 5-indolylgroup, 6-indolyl group, 7-indolyl group, 1-isoindolyl group,2-isoindolyl group, 3-isoindolyl group, 4-isoindolyl group, 5-isoindolylgroup, 6-isoindolyl group, 7-isoindolyl group, 2-furyl group, 3-furylgroup, 2-benzofuranyl group, 3-benzofuranyl group, 4-benzofuranyl group,5-benzofuranyl group, 6-benzofuranyl group, 7-benzofuranyl group,1-isobenzofuranyl group, 3-isobenzofuranyl group, 4-isobenzofuranylgroup, 5-isobenzofuranyl group, 6-isobenzofuranyl group,7-isobenzofuranyl group, quinolyl group, 3-quinolyl group, 4-quinolylgroup, 5-quinolyl group, 6-quinolyl group, 7-quinolyl group, 8-quinolylgroup, 1-isoquinolyl group, 3-isoquinolyl group, 4-isoquinolyl group,5-isoquinolyl group, 6-isoquinolyl group, 7-isoquinolyl group,8-isoquinolyl group, 2-quinoxalinyl group, 5-quinoxalinyl group,6-quinoxalinyl group, 1-carbazolyl group, 2-carbazolyl group,3-carbazolyl group, 4-carbazolyl group, 9-carbazolyl group,1-phenanthridinyl group, 2-phenanthridinyl group, 3-phenanthridinylgroup, 4-phenanthridinyl group, 6-phenanthridinyl group,7-phenanthridinyl group, 8-phenanthridinyl group, 9-phenanthridinylgroup, 10-phenanthridinyl group, 1-acridinyl group, 2-acridinyl group,3-acridinyl group, 4-acridinyl group, 9-acridinyl group,1,7-phenanthroline-2-yl group, 1,7-phenanthroline-3-yl group,1,7-phenanthroline-4-yl group, 1,7-phenanthroline-5-yl group,1,7-phenanthroline-6-yl group, 1,7-phenanthroline-8-yl group,1,7-phenanthroline-9-yl group, 1,7-phenanthroline-10-yl group,1,8-phenanthroline-2-yl group, 1,8-phenanthroline-3-yl group,1,8-phenanthroline-4-yl group, 1,8-phenanthroline-5-yl group,1,8-phenanthroline-6-yl group, 1,8-phenanthroline-7-yl group,1,8-phenanthroline-9-yl group, 1,8-phenanthroline-10-yl group,1,9-phenanthroline-2-yl group, 1,9-phenanthroline-3-yl group,1,9-phenanthroline-4-yl group, 1,9-phenanthroline-5-yl group,1,9-phenanthroline-6-yl group, 1,9-phenanthroline-7-yl group,1,9-phenanthroline-8-yl group, 1,9-phenanthroline-10-yl group,1,10-phenanthroline-2-yl group, 1,10-phenanthroline-3-yl group,1,10-phenanthroline-4-yl group, 1,10-phenanthroline -6-yl group,2,9-phenanthroline-1-yl group, 2,9-phenanthroline-3-yl group,2,9-phenanthroline-4-yl group, 2,9-phenanthroline-5-yl group,2,9-phenanthroline-6-yl group, 2,9-phenanthroline-7-yl group,2,9-phenanthroline-8-yl group, 2,9-phenanthroline-10-yl group,2,8-phenanthroline-1-yl group, 2,8-phenanthroline-3-yl group,2,8-phenanthroline-4-yl group, 2,8-phenanthroline-5-yl group,2,8-phenanthroline-6-yl group, 2,8-phenanthroline-7-yl group,2,8-phenanthroline-9-yl group, 2,8-phenanthroline-10-yl group,2,7-phenanthroline-1-yl group, 2,7-phenanthroline-3-yl group,2,7-phenanthroline-4-yl group, 2,7-phenanthroline-5-yl group,2,7-phenanthroline-6-yl group, 2,7-phenanthroline-8-yl group,2,7-phenanthroline-9-yl group, 2,7-phenanthroline-10-yl group,1-phenazinyl group, 2-phenazinyl group, 1-phenothiazinyl group,2-phenothiazinyl group, 3-phenothiazinyl group, 4-phenothiazinyl group,10-phenothiazinyl group, 1-phenoxazinyl group, 2-phenoxazinyl group,3-phenoxazinyl group, 4-phenoxazinyl group, 10-phenoxazinyl group,2-oxazolyl group, 4-oxazolyl group, 5-oxazolyl group, 2-oxadiazolylgroup, 5-oxadiazolyl group, 3-furazanyl group, 2-thienyl group,3-thienyl group, 2-methylpyrrole-1-yl group, 2-methylpyrrole-3-yl group,2-methylpyrrole-4-yl group, 2-methylpyrrole-5-yl group,3-methylpyrrole-1-yl group, 3-methylpyrrole-2-yl group, 3-methylpyrrole-4-yl group, 3-methylpyrrole-5-yl group, 2-t-butylpyrrole-4-yl group,3-(2-phenylpropyl)pyrrole-1-yl group, 2-methyl-1-indolyl group,4-methyl-1-indolyl group, 2-methyl-3-indolyl group, 4-methyl-3-indolylgroup, 2-t-butyl-1-indolyl group, 4-t-butyl -1-indolyl group,2-t-butyl-3-indolyl group, and 4-t-butyl-3-indolyl group, with phenylgroup, naphthyl group, biphenyl group, anthranyl group, phenanthrylgroup, pyrenyl group, chrysenyl group, fluoranthenyl group, andfluorenyl group being preferred.

L is a bonding group such as arylene group (inclusive of heteroarylenegroup) having 5 to 50 ring atoms which is optionally substituted or abivalent group composed of two or more arylene groups which are bondedto each other via a single bond, ether linkage, thioether linkage,alkylene group having 1 to 20 carbon atoms, alkenylene group having 2 to20 carbon atoms or amino linkage. Examples of the arylene group having 5to 50 ring atoms include 1,4-phenylene group, 1,2-phenylene group,1,3-phenylene group, 1,4-naphthylene group, 2,6-naphthylene group,1,5-naphthylene group, 9,10-anthranylene group, 9,10-phenanthrenylenegroup, 3,6-phenanthrenylene group, 1,6-pyrenylene group, 2,7-pyrenylenegroup, 6,12-chrysenylene group, 4,4′-biphenylene group, 3,3′-biphenylenegroup, 2,2′-biphenylene group, 2,7-fluorenylene group, 2,5-thiophenylenegroup, 2,5-silolylene group, and 2,5-oxadiazolylene group, with1,4-phenylene group, 1,2-phenylene group, 1,3-phenylene group,1,4-naphthylene group, 9,10-anthranylene group, 6,12-chrysenylene group,4,4′-biphenylene group, 3,3′-biphenylene group, 2,2′-biphenylene group,and 2,7-fluorenylene group being preferred.

When L is a bonding group composed of two or more arylene groups, theadjacent couple of arylene groups may be bonded via a bivalent group toform a new ring. The bivalent group for forming such ring may includetetramethylene group, pentamethylene group, hexamethylene group,diphenylmethane-2,2′-diyl group, diphenylethane-3,3′-diyl group, anddiphenylpropane-4,4′-diyl group.

Examples of the substituent group for Ar¹ to Ar⁴ and L include arylgroup (inclusive of heteroaryl group) having 5 to 50 ring atoms which isoptionally substituted, alkyl group having 1 to 50 carbon atoms which isoptionally substituted, alkoxy group having 1 to 50 carbon atoms whichis optionally substituted, aralkyl group having 7 to 50 carbon atomswhich is optionally substituted, aryloxy group (inclusive ofheteroaryloxy group) having 5 to 50 ring atoms which is optionallysubstituted, arylthio group (inclusive of heteroarylthio group) having 5to 50 ring atoms which is optionally substituted, alkoxycarbonyl grouphaving 2 to 50 carbon atoms which is optionally substituted, amino groupsubstituted with aryl group (inclusive of heteroaryl group) having 5 to50 ring atoms which is optionally substituted, halogen group, cyanogroup, nitro group, and hydroxyl group.

Examples of the aryl group having 5 to 50 ring atoms which is optionallysubstituted include phenyl group, 1-naphthyl group, 2-naphthyl group,1-anthryl group, 2-anthryl group, 9-anthryl group, 1-phenanthryl group,2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group,9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group,9-naphthacenyl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group,2-biphenylyl group, 3-biphenylyl group, 4-biphenylyl group,p-terphenyl-4-yl group, p-terphenyl-3-yl group, p-terphenyl-2-yl group,m-terphenyl-4-yl group, m-terphenyl-3-yl group, m-terphenyl-2-yl group,o-tolyl group, m-tolyl group, p-tolyl group, p-t-butylphenyl group,p-(2-phenylpropyl)phenyl group, 3-methyl-2-naphthyl group,4-methyl-1-naphthyl group, 4-methyl-1-anthryl group, 4′-methylbiphenylylgroup, 4″-t-butyl-p-terphenyl-4-yl group, fluoranthenyl group, fluorenylgroup, 1-pyrrolyl group, 2-pyrrolyl group, 3-pyrrolyl group, pyrazinylgroup, 2-pyridinyl group, 3-pyridinyl group, 4-pyridinyl group,1-indolyl group, 2-indolyl group, 3-indolyl group, 4-indolyl group,5-indolyl group, 6-indolyl group, 7-indolyl group, 1-isoindolyl group,2-isoindolyl group, 3-isoindolyl group, 4-isoindolyl group, 5-isoindolylgroup, 6-isoindolyl group, 7-isoindolyl group; 2-furyl group, 3-furylgroup, 2-benzofuranyl group, 3-benzofuranyl group, 4-benzofuranyl group,5-benzofuranyl group, 6-benzofuranyl group, 7-benzofuranyl group,1-isobenzofuranyl group, 3-isobenzofuranyl group, 4-isobenzofuranylgroup, 5-isobenzofuranyl group, 6-isobenzofuranyl group,7-isobenzofuranyl group, quinolyl group, 3-quinolyl group, 4-quinolylgroup, 5-quinolyl group, 6-quinolyl group, 7-quinolyl group, 8-quinolylgroup, 1-isoquinolyl group, 3-isoquinolyl group, 4-isoquinolyl group,5-isoquinolyl group, 6-isoquinolyl group, 7-isoquinolyl group,8-isoquinolyl group, 2-quinoxalinyl group, 5-quinoxalinyl group,6-quinoxalinyl group, 1-carbazolyl group, 2-carbazolyl group,3-carbazolyl group, 4-carbazolyl group, 9-carbazolyl group,1-phenanthridinyl group, 2-phenanthridinyl group, 3-phenanthridinylgroup, 4-phenanthridinyl group, 6-phenanthridinyl group,7-phenanthridinyl group, 8-phenanthridinyl group, 9-phenanthridinylgroup, 10-phenanthridinyl group, 1-acridinyl group, 2-acridinyl group,3-acridinyl group, 4-acridinyl group, 9-acridinyl group,1,7-phenanthroline-2-yl group, 1,7-phenanthroline -3-yl group,1,7-phenanthroline-4-yl group, 1,7-phenanthroline-5-yl group,1,7-phenanthroline-6-yl group, 1,7-phenanthroline-8-yl group,1,7-phenanthroline-9-yl group, 1,7-phenanthroline-10-yl group,1,8-phenanthroline-2-yl group, 1,8-phenanthroline-3-yl group,1,8-phenanthroline-4-yl group, 1,8-phenanthroline-5-yl group,1,8-phenanthroline-6-yl group, 1,8-phenanthroline-7-yl group,1,8-phenanthroline-9-yl group, 1,8-phenanthroline-10-yl group,1,9-phenanthroline-2-yl group, 1,9-phenanthroline-3-yl group,1,9-phenanthroline-4-yl group, 1,9-phenanthroline-5-yl group,1,9-phenanthroline-6-yl group, 1,9-phenanthroline-7-yl group,1,9-phenanthroline-8-yl group, 1,9-phenanthroline-10-yl group,1,10-phenanthroline-2-yl group, 1,10-phenanthroline-3-yl group,1,10-phenanthroline-4-yl group, 1,10-phenanthroline-5-yl group,2,9-phenanthroline-1-yl group, 2,9-phenanthroline-3-yl group,2,9-phenanthroline-4-yl group, 2,9-phenanthroline-5-yl group,2,9-phenanthroline-6-yl group, 2,9-phenanthroline-7-yl group,2,9-phenanthroline-8-yl group, 2,9-phenanthroline-10-yl group,2,8-phenanthroline-1-yl group, 2,8-phenanthroline-3-yl group,2,8-phenanthroline-4-yl group, 2,8-phenanthroline-5-yl group,2,8-phenanthroline-6-yl group, 2,8-phenanthroline-7-yl group,2,8-phenanthroline-9-yl group, 2,8-phenanthroline-10-yl group,2,7-phenanthroline-1yl group, 2,7-phenanthroline-3-yl group,2,7-phenanthroline-4-yl group, 2,7-phenarithroline-5-yl group,2,7-phenanthroline-6-yl group, 2,7-phenanthroline-8-yl group,2,7-phenanthroline-9-yl group, 2,7-phenanthroline-10-yl group,1-phenazinyl group, 2-phenazinyl group, 1-phenothiazinyl group,2-phenothiazinyl group, 3-phenothiazinyl group, 4-phenothiazinyl group,10-phenothiazinyl group, 1-phenoxazinyl group, 2-phenoxazinyl group,3-phenoxazinyl group, 4-phenoxazinyl group, 10-phenoxazinyl group,2-oxazolyl group, 4-oxazolyl group, 5-oxazolyl group, 2-oxadiazolylgroup, 5-oxadiazolyl group, 3-furazanyl group, 2-thienyl group,3-thienyl group, 2-methylpyrrole-1-yl group, 2-methylpyrrole-3-yl group,2-methylpyrrole-4-yl group, 2-methylpyrrole-5-yl group,3-methylpyrrole-1-yl group, 3-methylpyrrole-2-yl group,3-methylpyrrole-4-yl group, 3-methylpyrrole-5-yl group,2-t-butylpyrrole-4-yl group, 3-(2-phenylpropyl)pyrrole-1-yl group,2-methyl-1-indolyl group, 4-methyl-1-indolyl group, 2-methyl-3-indolylgroup, 4-methyl-3-indolyl group, 2-t-butyl-1-indolyl group,4-t-butyl-1-indolyl group, 2-t-butyl-3-indolyl group, and4-t-butyl-3-indolyl group.

Examples of the alkyl group having 1 to 50 carbon atoms which isoptionally substituted include methyl group, ethyl group, propyl group,isopropyl group, n-butyl group, s-butyl group, isobutyl group, t-butylgroup, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group,hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group,2-hydroxyisobutyl group, 1,2-dihydroxyethyl group,1,3-dihydroxyisopropyl group, 2,3-dihydroxy-t-butyl group,1,2,3-trihydroxypropyl group, chloromethyl group, 1-chloroethyl group,2-chloroethyl group, 2-chloroisobutyl group, 1,2-dichloroethyl group,1,3-dichloroisopropyl group, 2,3-dichloro-t-butyl group,1,2,3-trichloropropyl group, bromomethyl group, 1-bromoethyl group,2-bromoethyl group, 2-bromoisobutyl group, 1,2-dibromoethyl group,1,3-dibromoisopropyl group, 2,3-dibromo-t-butyl group,1,2,3-tribromopropyl group, iodomethyl group, 1-iodoethyl group,2-iodoethyl group, 2-iodoisobutyl group, 1,2-diiodoethyl group,1,3-diiodoisopropyl group, 2,3-diiodo-t-butyl group, 1,2,3-triiodopropylgroup, aminomethyl group, 1-aminoethyl group, 2-aminoethyl group,2-aminoisobutyl group, 1,2-diaminoethyl group, 1,3-diaminoisopropylgroup, 2,3-diamino-t-butyl group, 1,2,3-triaminopropyl group,cyanomethyl group, 1-cyanoethyl group, 2-cyanoethyl group,2-cyanoisobutyl group, 1,2-dicyanoethyl group, 1,3-dicyanoisopropylgroup, 2,3-dicyano-t-butyl group, 1,2,3-tricyanopropyl group,nitromethyl group, 1-nitroethyl group, 2-nitroethyl group,2-nitroisobutyl group, 1,2-dinitroethyl group, 1,3-dinitroisopropylgroup, 2,3-dinitro-t-butyl group, 1,2,3-trinitropropyl group,cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexylgroup, 4-methylcyclohexyl group, 1-adamantyl group, 2-adamantyl group,1-norbornyl group, and 2-norbornyl group.

The alkoxy group having 1 to 50 carbon atoms which is optionallysubstituted is represented by —OY, wherein Y is methyl group, ethylgroup, propyl group, isopropyl group, n-butyl group, s-butyl group,isobutyl group, t-butyl group, n-pentyl group, n-hexyl group, n-heptylgroup, n-octyl group, hydroxymethyl group, 1-hydroxyethyl group,2-hydroxyethyl group, 2-hydroxyisobutyl group, 1,2-dihydroxyethyl group,1,3-dihydroxyisopropyl group, 2,3-dihydroxy-t-butyl group,1,2,3-trihydroxypropyl group, chloromethyl group, 1-chloroethyl group,2-chloroethyl group, 2-chloroisobutyl group, 1,2-dichloroethyl group,1,3-dichloroisopropyl group, 2,3-dichloro-t-butyl group,1,2,3-trichloropropyl group, bromomethyl group, 1-bromoethyl group,2-bromoethyl group, 2-bromoisobutyl group, 1,2-dibromoethyl group,1,3-dibromoisopropyl group, 2,3-dibromo-t-butyl group,1,2,3-tribromopropyl group, iodomethyl group, 1-iodoethyl group,2-iodoethyl group, 2-iodoisobutyl group, 1,2-diiodoethyl group,1,3-diiodoisopropyl group, 2,3-diiodo-t-butyl group, 1,2,3-triiodopropylgroup, aminomethyl group, 1-aminoethyl group, 2-aminoethyl group,2-aminoisobutyl group, 1,2-diaminoethyl group, 1,3-diaminoisopropylgroup, 2,3-diamino-t-butyl group, 1,2,3-triaminopropyl group,cyanomethyl group, 1-cyanoethyl group, 2-cyanoethyl group,2-cyanoisobutyl group, 1,2-dicyanoethyl group, 1,3-dicyanoisopropylgroup, 2,3-dicyano-t-butyl group, 1,2,3-tricyanopropyl group,nitromethyl group, 1-nitroethyl group, 2-nitroethyl group,2-nitroisobutyl group, 1,2-dinitroethyl group, 1,3-dinitroisopropylgroup, 2,3-dinitro-t-butyl group, or 1,2,3-trinitropropyl group.

Examples of the aralkyl group having 7 to 50 carbon atoms which isoptionally substituted include benzyl group, 1-phenylethyl group,2-phenylethyl group, 1-phenylisopropyl group, 2-phenylisopropyl group,phenyl-t-butyl group, α-naphthylmethyl group, 1-α-naphthylethyl group,2-α-naphthylethyl group, 1-α-naphthylisopropyl group,2-α-naphthylisopropyl group, β-naphthylmethyl group, 1-β-naphthylethylgroup, 2-β-naphthylethyl group, 1-β-naphthylisopropyl group,2-β-naphthylisopropyl group, 1-pyrrolylmethyl group, 2-(1-pyrrolyl)ethylgroup, p-methylbenzyl group, m-methylbenzyl group, o-methylbenzyl group,p-chlorobenzyl group, m-chlorobenzyl group, o-chlorobenzyl group,p-bromobenzyl group, m-bromobenzyl group, o-bromobenzyl group, p-iodobenzyl group, m-iodobenzyl group, o-iodobenzyl group,p-hydroxybenzyl group, m-hydroxybenzyl group, o-hydroxybenzyl group,p-aminobenzyl group, m-aminobenzyl group, o-aminobenzyl group,p-nitrobenzyl group, m-nitrobenzyl group, o-nitrobenzyl group,p-cyanobenzyl group, m-cyanobenzyl group, o-cyanobenzyl group,1-hydroxy-2-phenylisopropyl group, and 1-chloro-2-phenylisopropyl group.

The aryloxy group having 5 to 50 ring atoms which is optionallysubstituted is represented by —OY′, wherein Y′ is phenyl group,1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group,9-anthryl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthrylgroup, 4-phenanthryl group, 9-phenanthryl group, 1-naphthacenyl group,2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl group, 2-pyrenylgroup, 4-pyrenyl group, 2-biphenylyl group, 3-biphenylyl group,4-biphenylyl group, p-terphenyl-4-yl group, p-terphenyl-3-yl group,p-terphenyl-2-yl group, m-terphenyl-4-yl group, m-terphenyl-3-yl group,m-terphenyl-2-yl group, o-tolyl group, m-tolyl group, p-tolyl group,p-t-butylphenyl group, p-(2-phenylpropyl)phenyl group,3-methyl-2-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl-1-anthrylgroup, 4′-methylbiphenylyl group, 4″-t-butyl-p-terphenyl-4-yl group,2-pyrrolyl group, 3-pyrrolyl group, pyrazinyl group, 2-pyridinyl group,3-pyridinyl group, 4-pyridinyl group, 2-indolyl group, 3-indolyl group,4-indolyl group, 5-indolyl group, 6-indolyl group, 7-indolyl group,1-isoindolyl group, 3-isoindolyl group, 4-isoindolyl group, 5-isoindolylgroup, 6-isoindolyl group, 7-isoindolyl group, 2-furyl group, 3-furylgroup, 2-benzofuranyl group, 3-benzofuranyl group, 4-benzofuranyl group,5-benzofuranyl group, 6-benzofuranyl group, 7-benzofuranyl group,1-isobenzofuranyl group, 3-isobenzofuranyl group, 4-isobenzofuranylgroup, 5-isobenzofuranyl group, 6-isobenzofuranyl group,7-isobenzofuranyl group, 2-quinolyl group, 3-quinolyl group, 4-quinolylgroup, 5-quinolyl group, 6-quinolyl group, 7-quinolyl group, 8-quinolylgroup, 1-isoquinolyl group, 3-isoquinolyl group, 4-isoquinolyl group,5-isoquinolyl group, 6-isoquinolyl group, 7-isoquinolyl group,8-isoquinolyl group, 2-quinoxalinyl group, 5-quinoxalinyl group,6-quinoxalinyl group, 1-carbazolyl group, 2-carbazolyl group,3-carbazolyl group, 4-carbazolyl group, 1-phenanthridinyl group,2-phenanthridinyl group, 3-phenanthridinyl group, 4-phenanthridinylgroup, 6-phenanthridinyl group, 7-phenanthridinyl group,8-phenanthridinyl group, 9-phenanthridinyl group, 10-phenanthridinylgroup, 1-acridinyl group, 2-acridinyl group, 3-acridinyl group,4-acridinyl group, 9-acridinyl group, 1,7-phenanthroline-2-yl group,1,7-phenanthroline-3-yl group, 1,7-phenanthroline-4-yl group,1,7-phenanthroline-5-yl group, 1,7-phenanthroline-6-yl group,1,7-phenanthroline-8-yl group, 1,7-phenanthroline-9-yl group,1,7-phenanthroline-10-yl group, 1,8-phenanthroline-2-yl group,1,8-phenanthroline-3-yl group, 1,8-phenanthroline-4-yl group,1,8-phenanthroline-5-yl group, 1,8-phenanthroline-6-yl group,1,8-phenanthroline-7-yl group, 1,8-phenanthroline-9-yl group,1,8-phenanthroline-10-yl group, 1,9-phenanthroline-2-yl group,1,9-phenanthroline-3-yl group, 1,9-phenanthroline-4-yl group,1,9-phenanthroline-5-yl group, 1,9-phenanthroline -6-yl group,1,9-phenanthroline-7-yl group, 1,9-phenanthroline-8-yl group,1,9-phenanthroline-10-yl group, 1,10-phenanthroline-2-yl group,1,10-phenanthroline-3-yl group, 1,10-phenanthroline-4-yl group,1,10-phenanthroline-5-yl group, 2,9-phenanthroline-1-yl group,2,9-phenanthroline-3-yl group, 2,9-phenanthroline-4-yl group,2,9-phenanthroline-5-yl group, 2,9-phenanthroline-6-yl group,2,9-phenanthroline-7-yl group, 2,9-phenanthroline-8-yl group,2,9-phenanthroline-10-yl group, 2,8-phenanthroline-1-yl group,2,8-phenanthroline-3-yl group, 2,8-phenanthroline-4-yl group,2,8-phenanthroline-5-yl group, 2,8-phenanthroline-6-yl group,2,8-phenanthroline-7-yl group, 2,8-phenanthroline-9-yl group,2,8-phenanthroline-10-yl group, 2,7-phenanthroline-1-yl group,2,7-phenanthroline-3-yl group, 2,7-phenanthroline-4-yl group,2,7-phenanthroline-5-yl group, 2,7-phenanthroline-6-yl group,2,7-phenanthroline-8-yl group, 2,7-phenanthroline-9-yl group,2,7-phenanthroline-10-yl group, 1-phenazinyl group, 2-phenazinyl group,1-phenothiazinyl group, 2-phenothiazinyl group, 3-phenothiazinyl group,4-phenothiazinyl group, 1-phenoxazinyl group, 2-phenoxazinyl group,3-phenoxazinyl group, 4-phenoxazinyl group, 2-oxazolyl group, 4-oxazolylgroup, 5-oxazolyl group, 2-oxadiazolyl group, 5-oxadiazolyl group,3-furazanyl group, 2-thienyl group, 3-thienyl group,2-methylpyrrole-1-yl group, 2-methylpyrrole-3-yl group,2-methylpyrrole-4-yl group, 2-methylpyrrole-5-yl group,3-methylpyrrole-1-yl group, 3-methylpyrrole-2-yl group,3-methylpyrrole-4-yl group, 3-methylpyrrole-5-yl group,2-t-butylpyrrole-4-yl group, 3-(2-phenylpropyl)pyrrole-1-yl group,2-methyl-1-indolyl group, 4-methyl-1-indolyl group, 2-methyl-3-indolylgroup, 4-methyl-3-indolyl group, 2-t-butyl-1-indolyl group,4-t-butyl-1-indolyl group, 2-t-butyl-3-indolyl group, or4-t-butyl-3-indolyl group.

The arylthio group having 5 to 50 ring atoms which is optionallysubstituted is represented by —SY″, wherein Y″ is phenyl group,1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group,9-anthryl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthrylgroup, 4-phenanthryl group, 9-phenanthryl group, 1-naphthacenyl group,2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl group, 2-pyrenylgroup, 4-pyrenyl group, 2-biphenylyl group, 3-biphenylyl group,4-biphenylyl group, p-terphenyl-4-yl group, p-terphenyl-3-yl group,p-terphenyl-2-yl group, m-terphenyl-4-yl group, m-terphenyl-3-yl group,m-terphenyl-2-yl group, o-tolyl group, m-tolyl group, p-tolyl group,p-t-butylphenyl group, p-(2-phenylpropyl)phenyl group,3-methyl-2-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl-1-anthrylgroup, 4′-methylbiphenylyl group, 4″-t-butyl-p-terphenyl-4-yl group,2-pyrrolyl group, 3-pyrrolyl group, pyrazinyl group, 2-pyridinyl group,3-pyridinyl group, 4-pyridinyl group, 2-indolyl group, 3-indolyl group,4-indolyl group, 5-indolyl group, 6-indolyl group, 7-indolyl group,1-isoindolyl group, 3-isoindolyl group, 4-isoindolyl group, 5-isoindolylgroup, 6-isoindolyl group, 7-isoindolyl group, 2-furyl group, 3-furylgroup, 2-benzofuranyl group, 3-benzofuranyl group, 4-benzofuranyl group,5-benzofuranyl group, 6-benzofuranyl group, 7-benzofuranyl group,1-isobenzofuranyl group, 3-isobenzofuranyl group, 4-isobenzofuranylgroup, 5-isobenzofuranyl group, 6-isobenzofuranyl group,7-isobenzofuranyl group, 2-quinolyl group, 3-quinolyl group, 4-quinolylgroup, 5-quinolyl group, 6-quinolyl group, 7-quinolyl group, 8-quinolylgroup, 1-isoquinolyl group, 3-isoquinolyl group, 4-isoquinolyl group,5-isoquinolyl group, 6-isoquinolyl group, 7-isoquinolyl group,8-isoquinolyl group, 2-quinoxalinyl group, 5-quinoxalinyl group,6-quinoxalinyl group, 1-carbazolyl group, 2-carbazolyl group,3-carbazolyl group, 4-carbazolyl group, 1-phenanthridinyl group,2-phenanthridinyl group, 3-phenanthridinyl group, 4-phenanthridinylgroup, 6-phenanthridinyl group, 7-phenanthridinyl group,8-phenanthridinyl group, 9-phenanthridinyl group, 10-phenanthridinylgroup, 1-acridinyl group, 2-acridinyl group, 3-acridinyl group,4-acridinyl group, 9-acridinyl group, 1,7-phenanthroline-2-yl group,1,7-phenanthroline-3-yl group, 1,7-phenanthroline-4-yl group,1,7-phenanthroline-5-yl group, 1,7-phenanthroline-6-yl group,1,7-phenanthroline-8-yl group, 1,7-phenanthroline-9-yl group,1,7-phenanthroline-10-yl group, 1,8-phenanthroline-2-yl group,1,8-phenanthroline-3-yl group, 1,8-phenanthroline-4-yl group,1,8-phenanthroline-5-yl group, 1,8-phenanthroline-6-yl group,1,8-phenanthroline-7-yl group, 1,8-phenanthroline-9-yl group,1,8-phenanthroline-10-yl group, 1,9-phenanthroline-2-yl group,1,9-phenanthroline-3-yl group, 1,9-phenanthroline-4-yl group,1,9-phenanthroline-5-yl group, 1,9-phenanthroline-6-yl group,1,9-phenanthroline-7-yl group, 1,9-phenanthroline-8-yl group,1,9-phenanthroline-10-yl group, 1,10-phenanthroline-2-yl group,1,10-phenanthroline-3-yl group, 1,10-phenanthroline-4-yl group,1,10-phenanthroline-5-yl group, 2,9-phenanthroline-1-yl group,2,9-phenanthroline-3-yl group, 2,9-phenanthroline-4-yl group,2,9-phenanthroline-5-yl group, 2,9-phenanthroline-6-yl group,2,9-phenanthroline-7-yl group, 2,9-phenanthroline-8-yl group,2,9-phenanthroline-10-yl group, 2,8-phenanthroline-1-yl group,2,8-phenanthroline-3-yl group, 2,8-phenanthroline-4-yl group,2,8-phenanthroline-5-yl group, 2,8-phenanthroline-6-yl group,2,8-phenanthroline-7-yl group, 2,8-phenanthroline-9-yl group,2,8-phenanthroline-10-yl group, 2,7-phenanthroline-1-yl group,2,7-phenanthroline-3-yl group, 2,7-phenanthroline-4-yl group,2,7-phenanthroline-5-yl group, 2,7-phenanthroline-6-yl group,2,7-phenanthroline-8-yl group, 2,7-phenanthroline-9-yl group,2,7-phenanthroline-10-yl group, 1-phenazinyl group, 2-phenazinyl group,1-phenothiazinyl group, 2-phenothiazinyl group, 3-phenothiazinyl group,4-phenothiazinyl group, 1-phenoxazinyl group, 2-phenoxazinyl group,3-phenoxazinyl group, 4-phenoxazinyl group, 2-oxazolyl group, 4-oxazolylgroup, 5-oxazolyl group, 2-oxadiazolyl group, 5-oxadiazolyl group,3-furazanyl group, 2-thienyl group, 3-thienyl group,2-methylpyrrole-1-yl group, 2-methylpyrrole-3-yl group,2-methylpyrrole-4-yl group, 2-methylpyrrole-5-yl group,3-methylpyrrole-1-yl group, 3 methylpyrrole-2-yl group,3-methylpyrrole-4-yl group, 3-methylpyrrole-5-yl group,2-t-butylpyrrole-4-yl group, 3-(2-phenylpropyl)pyrrole-1-yl group,2-methyl-1-indolyl group, 4-methyl-1-indolyl group, 2-methyl-3-indolylgroup, 4-methyl-3-indolyl group, 2-t-butyl-1-indolyl group,4-t-butyl-1-indolyl group, 2-t-butyl-3-indolyl group, or4-t-butyl-3-indolyl group.

The alkoxycarbonyl group having 2 to 50 carbon atoms which is optionallysubstituted is represented by —COOZ, wherein Z is methyl group, ethylgroup, propyl group, isopropyl group, n-butyl group, s-butyl group,isobutyl group, t-butyl group, n-pentyl group, n-hexyl group, n-heptylgroup, n-octyl group, hydroxymethyl group, 1-hydroxyethyl group,2-hydroxyethyl group, 2-hydroxyisobutyl group, 1,2-dihydroxyethyl group,1,3-dihydroxyisopropyl group, 2,3-dihydroxy-t-butyl group,1,2,3-trihydroxypropyl group, chloromethyl group, 1-chloroethyl group,2-chloroethyl group, 2-chloroisobutyl group, 1,2-dichloroethyl group,1,3-dichloroisopropyl group, 2,3-dichloro-t-butyl group,1,2,3-trichloropropyl group, bromomethyl group, 1-bromoethyl group,2-bromoethyl group, 2-bromoisobutyl group, 1,2-dibromoethyl group,1,3-dibromoisopropyl group, 2,3-dibromo-t-butyl group,1,2,3-tribromopropyl group, iodomethyl group, 1-iodoethyl group,2-iodoethyl group, 2-iodoisobutyl group, 1,2-diiodoethyl group,1,3-diiodoisopropyl group, 2,3-diiodo-t-butyl group, 1,2,3-triiodopropylgroup, aminomethyl group, 1-aminoethyl group, 2-aminoethyl group,2-aminoisobutyl group, 1,2-diaminoethyl group, 1,3-diaminoisopropylgroup, 2,3-diamino-t-butyl group, 1,2,3-triaminopropyl group,cyanomethyl group, 1-cyanoethyl group, 2-cyanoethyl group,2-cyanoisobutyl group, 1,2-dicyanoethyl group, 1,3-dicyanoisopropylgroup, 2,3-dicyano -t-butyl group, 1,2,3-tricyanopropyl group,nitromethyl group, 1-nitroethyl group, 2-nitroethyl group,2-nitroisobutyl group, 1,2-dinitroethyl group, 1,3-dinitroisopropylgroup, 2,3-dinitro-t-butyl group, or 1,2,3-trinitropropyl group.

The amino group substituted with aryl group having 5 to 50 ring atomswhich is optionally substituted is represented by —NPQ, wherein P and Qare each phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthrylgroup, 2-anthryl group, 9-anthryl group, 1-phenanthryl group,2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group,9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group,9-naphthacenyl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group,2-biphenylyl group, 3-biphenylyl group, 4-biphenylyl group,p-terphenyl-4-yl group, p-terphenyl-3-yl group, p-terphenyl-2-yl group,m-terphenyl-4-yl group, m-terphenyl-3-yl group, m-terphenyl-2-yl group,o-tolyl group, m-tolyl group, p-tolyl group, p-t-butylphenyl group,p-(2-phenylpropyl)phenyl group, 3-methyl-2-naphthyl group,4-methyl-1-naphthyl group, 4-methyl-1-anthryl group, 4′-methylbiphenylylgroup, 4″-t-butyl-p-terphenyl-4-yl group, 2-pyrrolyl group, 3-pyrrolylgroup, pyrazinyl group, 2-pyridinyl group, 3-pyridinyl group,4-pyridinyl group, 2-indolyl group, 3-indolyl group, 4-indolyl group,5-indolyl group, 6-indolyl group, 7-indolyl group, 1-isoindolyl group,3-isoindolyl group, 4-isoindolyl group, 5-isoindolyl group, 6-isoindolylgroup, 7-isoindolyl group, 2-furyl group, 3-furyl group, 2-benzofuranylgroup, 3-benzofuranyl group, 4-benzofuranyl group, 5-benzofuranyl group,6-benzofuranyl group, 7-benzofuranyl group, 1-isobenzofuranyl group,3-isobenzofuranyl group, 4-isobenzofuranyl group, 5-isobenzofuranylgroup, 6-isobenzofuranyl group, 7-isobenzofuranyl group, 2-quinolylgroup, 3-quinolyl group, 4-quinolyl group, 5-quinolyl group, 6-quinolylgroup, 7-quinolyl group, 8-quinolyl group, 1-isoquinolyl group,3-isoquinolyl group, 4-isoquinolyl group, 5-isoquinolyl group,6-isoquinolyl group, 7-isoquinolyl group, 8-isoquinolyl group,2-quinoxalinyl group, 5-quinoxalinyl group, 6-quinoxalinyl group,1-carbazolyl group, 2-carbazolyl group, 3-carbazolyl group, 4-carbazolylgroup, 1-phenanthridinyl group, 2-phenanthridinyl group,3-phenanthridinyl group, 4-phenanthridinyl group, 6-phenanthridinylgroup, 7-phenanthridinyl group, 8-phenanthridinyl group,9-phenanthridinyl group, 10-phenanthridinyl group, 1-acridinyl group,2-acridinyl group, 3-acridinyl group, 4-acridinyl group, 9-acridinylgroup, 1,7-phenanthroline-2-yl group, 1,7-phenanthroline-3-yl group,1,7-phenanthroline-4-yl group, 1,7-phenanthroline-5-yl group,1,7-phenanthroline-6-yl group, 1,7-phenanthroline-8-yl group,1,7-phenanthroline-9-yl group, 1,7-phenanthroline-10-yl group,1,8-phenanthroline-2-yl group, 1,8-phenanthroline-3-yl group,1,8-phenanthroline-4-yl group, 1,8-phenanthroline-5-yl group,1,8-phenanthroline-6-yl group, 1,8-phenanthroline-7-yl group,1,8-phenanthroline-9-yl group, 1,8-phenanthroline-10-yl group,1,9-phenanthroline-2-yl group, 1,9-phenanthroline-3-yl group,1,9-phenanthroline-4-yl group, 1,9-phenanthroline-5-yl group,1,9-phenanthroline-6-yl group, 1,9-phenanthroline-7-yl group,1,9-phenanthroline-8-yl group, 1,9-phenanthroline-10-yl group,1,10-phenanthroline-2-yl group, 1,10-phenanthroline-3-yl group,1,10-phenanthroline-4-yl group, 1,10-phenanthroline-5-yl group,2,9-phenanthroline-1-yl group, 2,9-phenanthroline-3-yl group,2,9-phenanthroline-4-yl group, 2,9-phenanthroline-5-yl group,2,9-phenanthroline-6-yl group, 2,9-phenanthroline-7-yl group,2,9-phenanthroline-8-yl group, 2,9-phenanthroline-10-yl group,2,8-phenanthroline-1-yl group, 2,8-phenanthroline-3-yl group,2,8-phenanthroline-4-yl group, 2,8-phenanthroline 5-yl group,2,8-phenanthroline-6-yl group, 2,8-phenanthroline-7-yl group,2,8-phenanthroline-9-yl group, 2,8-phenanthroline-10-yl group,2,7-phenanthroline-1-yl group, 2,7-phenanthroline-3-yl group,2,7-phenanthroline-4-yl group, 2,7-phenanthroline-5-yl group,2,7-phenanthroline-6-yl group, 2,7-phenanthroline-8-yl group,2,7-phenanthroline-9-yl group, 2,7-phenanthroline -10-yl group,1-phenazinyl group, 2-phenazinyl group, 1-phenothiazinyl group,2-phenothiazinyl group, 3-phenothiazinyl group, 4-phenothiazinyl group,1-phenoxazinyl group, 2-phenoxazinyl group, 3-phenoxazinyl group,4-phenoxazinyl group, 2-oxazolyl group, 4-oxazolyl group, 5-oxazolylgroup, 2-oxadiazolyl group, 5-oxadiazolyl group, 3-furazanyl group,2-thienyl group, 3-thienyl group, 2-methylpyrrole-1-yl group,2-methylpyrrole-3-yl group, 2-methylpyrrole-4-yl group,2-methylpyrrole-5-yl group, 3-methylpyrrole-1-yl group,3-methylpyrrole-2-yl group, 3-methylpyrrole-4-yl group,3-methylpyrrole-5-yl group, 2-t-butylpyrrole-4-yl group,3-(2-phenylpropyl)pyrrole-1-yl group, 2-methyl-1-indolyl group,4-methyl-1-indolyl group, 2-methyl-3-indolyl group, 4-methyl-3-indolylgroup, 2-t-butyl-1-indolyl group, 4-t-butyl-1-indolyl group,2-t-butyl-3-indolyl group, or 4-t-butyl-3-indolyl group.

Examples of the compound of the formula I are shown below, although notlimited thereto.

In addition, the aromatic amine of the following formula II is suitableas the material for the hole injecting/transporting layer.

In the formula II, the definition of each of Ar₁ to Ar₃ is the same asthose of the Ar¹ to Ar⁴ in the formula I. Examples of the compound ofthe formula II are shown below, although not limited thereto.

The present invention will be described in more detail with reference tothe examples, However it should be noted that the scope of the presentinvention is not limited to the following examples.

SYNTHESIS EXAMPLE 1

Synthesis of Compound No. 4

(1) Synthesis of 2,8-dibromodibenzofuran

A three-necked flask was charged with dibenzofuran (100.91 g, 600 mmol)and 300 ml of AcOH and the contents were heated to 40° C. Then, asolution of Br₂ (191.8 g, 1200 mmol)/AcOH 300 ml was added dropwise.After stirring for 9 h at 40° C., the mixture was refluxed for 6 h.After the reaction, the reaction production solution was cooled to roomtemperature and added with 600 ml of water. The precipitate collected byfiltration was dissolved in toluene. The resultant solution was driedover anhydrous magnesium sulfate, filtrated and concentrated. Theobtained solid product was recrystallized from hexane five times toobtain the titled compound (62.83 g, 32% yield).

FD Mass Spectroscopy Analysis

C₁₂H₆Br₂O: calculated 325.6, found 326

(2) Synthesis of 2-bromo-8-carbazolyldibenzofuran

A three-necked flask was charged with 2,8-dibromodibenzofuran (39.12 g,120 mmol), carbazole (20.07 g, 120 mmol), K₃PO₄ (50.94 g, 240 mmol),copper iodide (11.43 g, 60 mmol), 1,2-trans-diaminocyclohexane (20.55 g,180 mmol), and 1,4-dioxane (120 ml), and the mixture was refluxed for 9h. After the reaction, the reaction product solution was cooled to roomtemperature and extracted with CH₂Cl₂ using a separatory funnel. Theextract was dried over anhydrous magnesium sulfate, filtrated andconcentrated. The obtained solid product was purified by a columnchromatography (hexane:toluene=8:2). The above operations were allperformed in an argon atmosphere (16.0 g, 32% yield),

FD Mass Spectroscopy Analysis

C₂₄H₁₄BrNO: calculated 412.3, found 412

(3) Synthesis of Compound No. 4

A three-necked flask was charged with compound 1a (7.7 mmol, 2.21 g),compound 1b (7 mmol, 2.89 g), Na₂CO₃ 2M aq. (7 ml), Pd[PPh₃]₄ (0.35mmol, 0.40 g), DME (14 ml), and toluene (7 ml), and the mixture wasrefluxed for 10 h. After the reaction, the reaction product solution wascooled to room temperature and extracted with CH₂Cl₂ using a separatoryfunnel. The extract was dried over anhydrous magnesium sulfate,filtrated and concentrated. The obtained solid product was purified by acolumn chromatography (hexane:toluene=6:4). The purified product wasfurther washed with ethanol and vacuum-dried to obtain a white solid.The above operations were all performed in an argon atmosphere (2.49 g,62% yield).

FD Mass Spectroscopy Analysis

C₄₂H₂₆N₂O: calculated 574.67, found 574

SYNTHESIS EXAMPLE 2

Synthesis of Compound No. 9

A three-necked flask was charged with compound 2a (6.3 mmol, 2.85 g),compound 1b (6 mmol, 2.47 g), Na₂CO₃ 2M aq. (6 ml), Pd[PPh₃]₄ (0.3 mmol,0.35 g), DME (12 ml), and toluene (6 ml), and the mixture was refluxedfor 9 h. After the reaction, the reaction product solution was cooled toroom temperature and extracted with CH₂Cl₂ using a separatory funnel.The extract was dried over anhydrous magnesium sulfate, filtrated andconcentrated. The obtained solid product was purified by a columnchromatography (hexane:toluene=6:4). The purified product was furtherwashed with ethanol and vacuum-dried to obtain a white solid. The aboveoperations were all performed in an argon atmosphere (2.12 g, 48%yield).

FD Mass Spectroscopy Analysis

C₅₄H₃₃N₃O: calculated 739.9, found 739

SYNTHESIS EXAMPLE 3

Synthesis of Compound No. 10

A three-necked flask was charged with compound 3a (7.35 mmol, 2.12 g),compound 1b (7 mmol, 2.89 g), Na₂CO₃ 2M aq. (7 ml), Pd[PPh₃]₄ (0.35mmol, 0.40 g), DME (14 ml), and toluene (7 ml), and the mixture wasrefluxed for 9 h. After the reaction, the reaction product solution wascooled to room temperature and extracted with CH₂Cl₂ using a separatoryfunnel. The extract was dried over anhydrous magnesium sulfate,filtrated and concentrated. The obtained solid product was purified by acolumn chromatography (hexane:toluene=6:4). The purified product wasfurther washed with ethanol and vacuum-dried to obtain a white solid.The above operations were all performed in an argon atmosphere (2.55 g,63% yield).

FD Mass Spectroscopy Analysis

C₄₂H₂₅NO₂: calculated 575.7, found 575

SYNTHESIS EXAMPLE 4

Synthesis of Compound No. 12

A three-necked flask was charged with compound 4a (6.6 mmol, 2.87 g),compound 1b (6 mmol, 2.47 g), Na₂CO₃ 2 M aq. (6 ml), Pd[PPh₃]₄ (0.3mmol, 0.35 g), DME (12 ml), and toluene (6 ml), and the mixture wasrefluxed for 9 h. After the reaction, the reaction product solution wascooled to room temperature and extracted with CH₂Cl₂ using a separatoryfunnel. The extract was dried over anhydrous magnesium sulfate,filtrated and concentrated. The obtained solid product was purified by acolumn chromatography (hexane:toluene=6:4). The purified product wasfurther washed with ethanol and vacuum-dried to obtain a white solid.The above operations were all performed in an argon atmosphere (2.70 g,61% yield).

FD Mass Spectroscopy Analysis

C₅₄H₃₂N₂O₂: calculated 740.84, found 740

The structures of the compounds synthesized in Synthesis Examples 1 to 4were confirmed by FD-MS (field desorption mass spectrometry).

Apparatus: HX110 manufactured by JEOL, Ltd.

Acceralation Voltage: 8 kV

Scan range: m/z=50 to 1500

Emitter material: carbon

Emitter current: 0 mA→2 mA/min→40 mA (maintained for 10 min)

EXAMPLE 1

Preparation of Organic EL Device

A glass substrate of 25 mm×75 mm×1.1 mm thickness having ITO transparentelectrode (manufactured by Asahi Glass Company Ltd.) was ultrasonicallycleaned in isopropyl alcohol for 5 min and then UV ozone-cleaned for 30min. The cleaned glass substrate having the transparent electrode lineswas mounted to a substrate holder of a vacuum vapor depositionapparatus. On the surface having the transparent electrode lines, a filmof HTM1 (see the formula below) having a thickness of 80 nm was firstdeposited by resistance heating so as to cover the transparentelectrode. The HTM1 film functioned as the hole transporting/holeinjecting layer. Then, Compound No. 4 as the host material and ComplexK-21 as the dopanat material were vapor co-depostited by resistanceheating to successively form a film having a thickness of 30 nm on theHTM1 film. The concentration of Complex K-21 was 7.5% by weight. Theco-deposited film functions as the light emitting layer. Then, an ETM1film having a thickness of 10 nm on the light emitting layer and an ETM2film having a thickness of 20 nm on the ETM1 film were successivelydeposited in layers. The ETM1 film and ETM2 film functioned as the firstand second electron transporting layer, respectively. Then, a LiFelectron injecting electrode (cathode) having a thickness of 0.5 nm wasdeposited at a film-depositing speed of 0.1 Å/min. Finally, a metallicAl was deposited on the LiF film to form a metal cathode having athickness of 150 nm, thereby obtaining an organic EL device.

Evaluation of Light Emitting Property of Organic EL Device

The organic EL device thus prepared was driven under a direct current toemit light and measured for the wave length (λ), the luminance (L) andthe current density to determine the current efficiency (L/J). Theresults at a current density of 1 mA/cm² are shown in Table 1.

EXAMPLES 2-8

Each organic EL device was prepared in the same manner as in Example 1except for using a host material listed in Table 1 in place of the hostCompound No. 4 used in Example 1. The results are shown in Table 1.

COMPARATIVE EXAMPLE 1

An organic EL device was prepared in the same manner as in Example 1except for using CBP as the host material in place of the host CompoundNo. 4 used in Example 1. The results are shown in Table 1.

COMPARATIVE EXAMPLE 2

An organic EL device was prepared in the same manner as in Example 1except for using the following compound X-1 described in WO 2005/113531in place of the host Compound No. 4 used in Example 1. The results areshown in Table 1.

TABLE 1

Volt- Lumi- Wave Host age nance L/J EQE length Compound (V) (cd/m²)(cd/A) (%) (nm) Examples 1 No. 4 6.2 190 19.0 8.3 481 2 No. 9 6.6 18218.2 7.7 480 3 No. 10 5.8 161 16.1 6.9 480 4 No. 12 6.0 170 17.0 7.3 4815 No. 24 6.2 163 16.3 7.0 479 6 No. 26 6.1 165 16.5 7.2 481 7 No. 55 5.7162 16.2 6.9 481 8 No. 64 6.1 152 15.2 6.4 480 Comparative Examples 1CBP 6.0  82  8.2 3.7 480 2 X-1 no emission of light

EXAMPLES 9-11

Application to Hole Transporting Layer

Each organic EL device was prepared in the same manner as in Example 1except for using the compound listed in Table 2 as the holetransporting/hole injecting layer in place of HTM1 and using thefollowing compound H-1 as the host material. The results are shown inTable 2.

COMPARATIVE EXAMPLE 3

An organic EL device was prepared in the same manner as in Example 9except for using NPD as the hole transporting material in place of thehole transporting Compound No. 4. The results are shown in Table 2.

TABLE 2

Hole Volt- Lumi- Wave Transporting age nance L/J EQE length Compound (V)(cd/m²) (cd/A) (%) (nm) Examples 9 No. 4 6.2 148 14.8 6.7 479 10 No. 96.4 144 14.4 6.5 479 11 No. 54 6.3 150 15.0 6.8 481 Comparative Examples3 NPD 6.5 101 10.1 4.6 480

As compared with the compounds used in examples, the compounds used incomparative examples were poor in the current efficiency and failed toallow the efficient emission of the dopant.

As described above, by using the material for organic EL devices of theinvention which is represented by the formulae 1 to 5, organic ELdevices having a high emitting efficiency, causing little pixel defects,being excellent in the heat resistance, and having a long lifetime areobtained. Therefore, such organic EL devices are very useful as thedisplay and light source for various electronic instruments.

What is claimed is:
 1. A material comprising at least one phosphorescentmetal complex, and a compound represented by the following formula (3):

wherein R₁ to R₃ are each independently hydrogen atom, halogen atom,alkyl group having 1 to 40 carbon atoms which is optionally substituted,cycloalkyl group having 3 to 15 carbon atoms which is optionallysubstituted, heterocyclic group having 3 to 20 carbon atoms which isoptionally substituted, alkoxy group having 1 to 40 carbon atoms whichis optionally substituted, non-condensed aryl group having 6 to 40carbon atoms which is optionally substituted, condensed aryl grouphaving 10 to 18 carbon atoms which is optionally substituted, aryloxygroup having 6 to 20 carbon atoms which is optionally substituted,aralkyl group having 7 to 20 carbon atoms which is optionallysubstituted, arylamino group having 6 to 40 carbon atoms which isoptionally substituted, alkylamino group having 1 to 40 carbon atomswhich is optionally substituted, aralkylamino group having 7 to 60carbon atoms which is optionally substituted, arylcarbonyl group having7 to 40 carbon atoms which is optionally substituted, arylthio grouphaving 6 to 20 carbon atoms which is optionally substituted, alkylhalide group having 1 to 40 carbon atoms which is optionallysubstituted, or cyano group, with the proviso that at least one of R₁ toR₃ is 9-carbazolyl group which is optionally substituted orazacarbazolyl group having 2 to 5 nitrogen atoms which is optionallysubstituted; R₆ and R₁₀ are each independently hydrogen atom or alkylgroup having 1 to 40 carbon atoms which is optionally substituted; R₇and R₉ are each independently hydrogen atom, halogen atom, alkyl grouphaving 1 to 40 carbon atoms which is optionally substituted, cycloalkylgroup having 3 to 15 carbon atoms which is optionally substituted,heterocyclic group having 3 to 20 carbon atoms which is optionallysubstituted, alkoxy group having 1 to 40 carbon atoms which isoptionally substituted, non-condensed aryl group having 6 to 40 carbonatoms which is optionally substituted, condensed aryl group having 10 to18 carbon atoms which is optionally substituted, aryloxy group having 6to 20 carbon atoms which is optionally substituted, aralkyl group having7 to 20 carbon atoms which is optionally substituted, arylamino grouphaving 6 to 40 carbon atoms which is optionally substituted, alkylaminogroup having 1 to 40 carbon atoms which is optionally substituted,aralkylamino group having 7 to 60 carbon atoms which is optionallysubstituted, arylcarbonyl group having 7 to 40 carbon atoms which isoptionally substituted, arylthio group having 6 to 20 carbon atoms whichis optionally substituted, alkyl halide group having 1 to 40 carbonatoms which is optionally substituted, or cyano group; the benzene ringbetween R₇ and R₉ and one of R₇ and R₉ together with the benzene ring towhich R₇ to R₉ are bonded do not form a carbazolyl group; each of R₁ toR₃, R₆, R₇, R₉ and R₁₀ does not have a polymerizable functional group atits terminal end; R₂₀ to R₂₄ are each independently hydrogen atom,halogen atom, alkyl group having 1 to 40 carbon atoms which isoptionally substituted, cycloalkyl group having 3 to 15 carbon atomswhich is optionally substituted, heterocyclic group having 3 to 20carbon atoms which is optionally substituted, alkoxy group having 1 to40 carbon atoms which is optionally substituted, non-condednsed arylgroup having 6 to 40 carbon atoms which is optionally substituted,condensed aryl group having 10 to 18 carbon atoms which is optionallysubstituted, aryloxy group having 6 to 20 carbon atoms which isoptionally substituted, aralkyl group having 7 to 20 carbon atoms whichis optionally substituted, arylamino group having 6 to 40 carbon atomswhich is optionally substituted, alkylamino group having 1 to 40 carbonatoms which is optionally substituted, aralkylamino group having 7 to 60carbon atoms which is optionally substituted, arylcarbonyl group having7 to 40 carbon atoms which is optionally substituted, arylthio grouphaving 6 to 20 carbon atoms which is optionally substituted, alkylhalide group having 1 to 40 carbon atoms which is optionallysubstituted, or cyano group; and X is a sulfur atom or an oxygen atom.2. The material according to claim 1, wherein at least one of R₇, R₉ andR₂₀ to R₂₄ of the formula (3) is a group selected from the groupconsisting of a substituted or non-substituted 9-carbazolyl group, asubstituted or non-substituted dibenzofuranyl group, a substituted ornon-substituted azacarbazolyl group having 2 to 5 nitrogen atoms and asubstituted or non-substituted dibenzothiophenyl group.
 3. The materialaccording to claim 1, wherein the compound represented by the formula(3) has a triplet energy gap of 2.2 to 3.2 eV.
 4. An organicelectroluminescence device which comprises a cathode, an anode and anorganic thin film layer having one or more layers, the organic thin filmlayer being interposed between the cathode and the anode, wherein atleast one of the layers of the organic thin film is a light emittinglayer which comprises a host material and at least one phosphorescentmetal complex or a phosphorescent material, and wherein at least one ofthe layers of the organic thin film comprises the material according toclaim
 1. 5. The organic electroluminescence device according to claim 4,wherein the light emitting layer comprises the host material and the atleast one phosphorescent metal complex, and wherein the host material isthe material.
 6. The organic electroluminescence device according toclaim 4, wherein at least one of the layers of the organic thin filmlayer is an electron injecting layer mainly comprising anitrogen-containing cyclic derivative which is different from thematerial.
 7. The organic electroluminescence device according to claim4, wherein at least one of the layers of the organic thin film layer isa hole transporting layer which comprises the material.
 8. The organicelectroluminescence device according to claim 4, which further comprisesa reducing dopant at an interface between the cathode and the organicthin film layer.
 9. The organic electroluminescence device according toclaim 4, wherein the light emitting layer comprises the host materialand the phosphorescent material, and wherein the host material is thematerial.
 10. The organic electroluminescence device according to claim9, wherein the phosphorescent material is a compound comprising iridium(Ir), osmium (Os) or platinum (Pt).
 11. The organic electroluminescencedevice according to claim 9, wherein the light emitting layer comprisinga metal complex which emits blue light having a maximum peak wavelengthof 500 nm or less.
 12. A material comprising at least one phosphorescentmetal complex, and a compound represented by the following formula (4):

wherein R₁ to R₃ are each independently hydrogen atom, halogen atom,alkyl group having 1 to 40 carbon atoms which is optionally substituted,cycloalkyl group having 3 to 15 carbon atoms which is optionallysubstituted, heterocyclic group having 3 to 20 carbon atoms which isoptionally substituted, alkoxy group having 1 to 40 carbon atoms whichis optionally substituted, non-condensed aryl group having 6 to 40carbon atoms which is optionally substituted, condensed aryl grouphaving 10 to 18 carbon atoms which is optionally substituted, aryloxygroup having 6 to 20 carbon atoms which is optionally substituted,aralkyl group having 7 to 20 carbon atoms which is optionallysubstituted, arylamino group having 6 to 40 carbon atoms which isoptionally substituted, alkylamino group having 1 to 40 carbon atomswhich is optionally substituted, aralkylamino group having 7 to 60carbon atoms which is optionally substituted, arylcarbonyl group having7 to 40 carbon atoms which is optionally substituted, arylthio grouphaving 6 to 20 carbon atoms which is optionally substituted, alkylhalide group having 1 to 40 carbon atoms which is optionallysubstituted, or cyano group, with the proviso that at least one of R₁ toR₃ is 9-carbazolyl group which is optionally substituted orazacarbazolyl group having 2 to 5 nitrogen atoms which is optionallysubstituted; R₆ is hydrogen atom or alkyl group having 1 to 40 carbonatoms which is optionally substituted; R₇ is hydrogen atom, halogenatom, alkyl group having 1 to 40 carbon atoms which is optionallysubstituted, cycloalkyl group having 3 to 15 carbon atoms which isoptionally substituted, heterocyclic group having 3 to 20 carbon atomswhich is optionally substituted, alkoxy group having 1 to 40 carbonatoms which is optionally substituted, non-condensed aryl group having 6to 40 carbon atoms which is optionally substituted, condensed aryl grouphaving 10 to 18 carbon atoms which is optionally substituted, aryloxygroup having 6 to 20 carbon atoms which is optionally substituted,aralkyl group having 7 to 20 carbon atoms which is optionallysubstituted, arylamino group having 6 to 40 carbon atoms which isoptionally substituted, alkylamino group having 1 to 40 carbon atomswhich is optionally substituted, aralkylamino group having 7 to 60carbon atoms which is optionally substituted, arylcarbonyl group having7 to 40 carbon atoms which is optionally substituted, arylthio grouphaving 6 to 20 carbon atoms which is optionally substituted, alkylhalide group having 1 to 40 carbon atoms which is optionallysubstituted, or cyano group, each of R₁ to R₃, R₆, and R₇ does not havea polymerizable functional group at its terminal end; R₁₈, R₁₉ and R₂₁to R₂₃ are each independently hydrogen atom, halogen atom, alkyl grouphaving 1 to 40 carbon atoms which is optionally substituted, cycloalkylgroup having 3 to 15 carbon atoms which is optionally substituted,heterocyclic group having 3 to 20 carbon atoms which is optionallysubstituted, alkoxy group having 1 to 40 carbon atoms which isoptionally substituted, non-condensed aryl group having 6 to 40 carbonatoms which is optionally substituted, condensed aryl group having 10 to18 carbon atoms which is optionally substituted, aryloxy group having 6to 20 carbon atoms which is optionally substituted, aralkyl group having7 to 20 carbon atoms which is optionally substituted, arylamino grouphaving 6 to 40 carbon atoms which is optionally substituted, alkylaminogroup having 1 to 40 carbon atoms which is optionally substituted,aralkylamino group having 7 to 60 carbon atoms which is optionallysubstituted, arylcarbonyl group having 7 to 40 carbon atoms which isoptionally substituted, arylthio group having 6 to 20 carbon atoms whichis optionally substituted, alkyl halide group having 1 to 40 carbonatoms which is optionally substituted, or cyano group; and X is a sulfuratom or an oxygen atom.
 13. The material according to claim 12, whereinat least one of R₇ and R₂₁ to R₂₃ of the formula (4) is a group selectedfrom the group consisting of a substituted or non-substituted9-carbazolyl group, a substituted or non-substituted dibenzofuranylgroup, a substituted or non-substituted azacarbazolyl group having 2 to5 nitrogen atoms and a substituted or non-substituted dibenzothiophenylgroup.
 14. The material according to claim 12, wherein the compoundrepresented by the formula (4) has a triplet energy gap of 2.2 to 3.2eV.
 15. An organic electroluminescence device which comprises a cathode,an anode and an organic thin film layer having one or more layers, theorganic thin film layer being interposed between the cathode and theanode, wherein at least one of the layers of the organic thin film is alight emitting layer which comprises a host material and at least onephosphorescent metal complex or a phosphorescent material, and whereinat least one of the layers of the organic thin film comprises thematerial according to claim
 12. 16. The organic electroluminescencedevice according to claim 15, wherein the light emitting layer comprisesthe host material and the at least one phosphorescent metal complex, andwherein the host material is the material.
 17. The organicelectroluminescence device according to claim 15, wherein at least oneof the layers of the organic thin film layer is an electron injectinglayer mainly comprising a nitrogen-containing cyclic derivative which isdifferent from the material.
 18. The organic electroluminescence deviceaccording to claim 15, wherein at least one of the layers of the organicthin film layer is a hole transporting layer which comprises thematerial.
 19. The organic electroluminescence device according to claim15, which further comprises a reducing dopant at an interface betweenthe cathode and the organic thin film layer.
 20. The organicelectroluminescence device according to claim 15, wherein the lightemitting layer comprises the host material and the phosphorescentmaterial, and wherein the host material is the material.
 21. The organicelectroluminescence device according to claim 20, wherein thephosphorescent material is a compound comprising iridium (Ir), osmium(Os) or platinum (Pt).
 22. The organic electroluminescence deviceaccording to claim 20, wherein the light emitting layer comprising ametal complex which emits blue light having a maximum peak wavelength of500 nm or less.
 23. A material comprising at least one phosphorescentmetal complex, and a compound represented by the following formula (5):

wherein R₁ to R₃ are each independently hydrogen atom, halogen atom,alkyl group having 1 to 40 carbon atoms which is optionally substituted,cycloalkyl group having 3 to 15 carbon atoms which is optionallysubstituted, heterocyclic group having 3 to 20 carbon atoms which isoptionally substituted, alkoxy group having 1 to 40 carbon atoms whichis optionally substituted, non-condensed aryl group having 6 to 40carbon atoms which is optionally substituted, condensed aryl grouphaving 10 to 18 carbon atoms which is optionally substituted, aryloxygroup having 6 to 20 carbon atoms which is optionally substituted,aralkyl group having 7 to 20 carbon atoms which is optionallysubstituted, arylamino group having 6 to 40 carbon atoms which isoptionally substituted, alkylamino group having 1 to 40 carbon atomswhich is optionally substituted, aralkylamino group having 7 to 60carbon atoms which is optionally substituted, arylcarbonyl group having7 to 40 carbon atoms which is optionally substituted, arylthio grouphaving 6 to 20 carbon atoms which is optionally substituted, alkylhalide group having 1 to 40 carbon atoms which is optionallysubstituted, or cyano group, with the proviso that at least one of R₁ toR₃ is 9-carbazolyl group which is optionally substituted orazacarbazolyl group having 2 to 5 nitrogen atoms which is optionallysubstituted; R₆ and R₁₀ are each independently hydrogen atom or alkylgroup having 1 to 40 carbon atoms which is optionally substituted; R₇and R₈ are each independently hydrogen atom, halogen atom, alkyl grouphaving 1 to 40 carbon atoms which is optionally substituted, cycloalkylgroup having 3 to 15 carbon atoms which is optionally substituted,heterocyclic group having 3 to 20 carbon atoms which is optionallysubstituted, alkoxy group having 1 to 40 carbon atoms which isoptionally substituted, non-condensed aryl group having 6 to 40 carbonatoms which is optionally substituted, condensed aryl group having 10 to18 carbon atoms which is optionally substituted, aryloxy group having 6to 20 carbon atoms which is optionally substituted, aralkyl group having7 to 20 carbon atoms which is optionally substituted, arylamino grouphaving 6 to 40 carbon atoms which is optionally substituted, alkylaminogroup having 1 to 40 carbon atoms which is optionally substituted,aralkylamino group having 7 to 60 carbon atoms which is optionallysubstituted, arylcarbonyl group having 7 to 40 carbon atoms which isoptionally substituted, arylthio group having 6 to 20 carbon atoms whichis optionally substituted, alkyl halide group having 1 to 40 carbonatoms which is optionally substituted, or cyano group; R₈ and thebenzene ring between R₈ and R₁₀ together with the benzene ring to whichR₈ is bonded do not form a carbazolyl group, and R₇ and R₈ together withthe benzene ring to which R₇ and R₈ are bonded do not form a carbazolylgroup; each of R₁ to R₃, R₆, R₇, R₈ and R₁₀ does not have apolymerizable functional group at its terminal end; R₂₀, R₂₂ to R₂₄ andR₂₅ to R₂₉ are each independently hydrogen atom, halogen atom, alkylgroup having 1 to 40 carbon atoms which is optionally substituted,cycloalkyl group having 3 to 15 carbon atoms which is optionallysubstituted, heterocyclic group having 3 to 20 carbon atoms which isoptionally substituted, alkoxy group having 1 to 40 carbon atoms whichis optionally substituted, non-condensed aryl group having 6 to 40carbon atoms which is optionally substituted, condensed aryl grouphaving 10 to 18 carbon atoms which is optionally substituted, aryloxygroup having 6 to 20 carbon atoms which is optionally substituted,aralkyl group having 7 to 20 carbon atoms which is optionallysubstituted, arylamino group having 6 to 40 carbon atoms which isoptionally substituted, alkylamino group having 1 to 40 carbon atomswhich is optionally substituted, aralkylamino group having 7 to 60carbon atoms which is optionally substituted, arylcarbonyl group having7 to 40 carbon atoms which is optionally substituted, arylthio grouphaving 6 to 20 carbon atoms which is optionally substituted, alkylhalide group having 1 to 40 carbon atoms which is optionallysubstituted, or cyano group; at least one of R₇, R₈, R₂₀ and R₂₂ to R₂₉is a group selected from the group consisting of a substituted ornon-substituted 9-carbazolyl group, a substituted or non-substituteddibenzofuranyl group, a substituted or non-substituted azacarbazolylgroup having 2 to 5 nitrogen atoms and a substituted or non-substituteddibenzothiophenyl group; and X is a sulfur atom or an oxygen atom. 24.The material according to claim 23, wherein the compound represented bythe formula (5) has a triplet energy gap of 2.2 to 3.2 eV.
 25. Anorganic electroluminescence device which comprises a cathode, an anodeand an organic thin film layer having one or more layers, the organicthin film layer being interposed between the cathode and the anode,wherein at least one of the layers of the organic thin film is a lightemitting layer which comprises a host material and at least onephosphorescent metal complex or a phosphorescent material, and whereinat least one of the layers of the organic thin film comprises thematerial according to claim
 23. 26. The organic electroluminescencedevice according to claim 25, wherein the light emitting layer comprisesthe host material and the at least one phosphorescent metal complex, andwherein the host material is the material.
 27. The organicelectroluminescence device according to claim 25, wherein at least oneof the layers of the organic thin film layer is an electron injectinglayer mainly comprising a nitrogen-containing cyclic derivative which isdifferent from the material.
 28. The organic electroluminescence deviceaccording to claim 25, wherein at least one of the layers of the organicthin film layer is a hole transporting layer which comprises thematerial.
 29. The organic electroluminescence device according to claim25, which further comprises a reducing dopant at an interface betweenthe cathode and the organic thin film layer.
 30. The organicelectroluminescence device according to claim 25, wherein the lightemitting layer comprises the host material and the phosphorescentmaterial, and wherein the host material is the material.
 31. The organicelectroluminescence device according to claim 30, wherein thephosphorescent material is a compound comprising iridium (Ir), osmium(Os) or platinum (Pt).
 32. The organic electroluminescence deviceaccording to claim 30, wherein the light emitting layer comprising ametal complex which emits blue light having a maximum peak wavelength of500 nm or less.